Moderate Energy Restriction Research Articles

Interindividual variability in energy intake and expenditure during a weight loss intervention

IntroductionBehavioral compensations may occur as a response to a negative energy balance. The aim of this study was to explore the associations between changes in energy intake (EI) and changes in physical activity (PA, min/day; kcal/d) as a response to a weight loss (WL) intervention and to understand if interindividual differences occur in EI and energy expenditure (EE). MethodsEighty-one participants [mean (SD): age = 42.8 (9.4)y, BMI = 31.2 (4.4)kg/m2, 37% females] divided in intervention (IG, n = 43) and control group (CG, n = 38) were included. The IG underwent a moderate energy restriction (300–500 kcal/d). EI was measured through the intake-balance method. Non-exercise PA (NEPA) and exercise (through logbook) were assessed by accelerometery. The EE in NEPA (NEAT) and in exercise (EiEE) was calculated by applying the Freedson Combination’98 algorithm over the time spent in these activities. Pearson correlations were performed in IG to examine associations between EE components, EI and body composition. To understand if interindividual differences were observed, the SD of individual response (SDIR) and the smallest worthwhile change (SWC, SDbaselineCG×0.2) were calculated. ResultsChanges in EI [Δ EI, (kcal/d)] was negatively associated with Δ exercise (min/d:r = −0.413, p = 0.045; %:r = −0.846, p = 0.008) and with Δ EiEE (kcal/d:r = −0.488, p = 0.016; %:r = −0.859, p = 0.006). A negative correlation was found between Δ sedentary time and Δ NEPA (min/d:r = −0.622, p = 0.002; %:r = −0.487, p = 0.018). An interindividual variability was found for EI(SDIR = 151.6, SWC = 72.3) and EE (SDIR = 165, SWC = 134). ConclusionsDecreases in EI were not associated to compensatory responses such as decreases in PA and/or increases in sedentary time. Interindividual variability was found for EI and EE. Nevertheless, behavioral compensations and the interindividual variability should be considered when implementing WL interventions, to increase the likelihood of achieving sustainable results. (clinicaltrials.gov ID: NCT03031951)

Effects of combined training or moderate intensity continuous training during a 3-week multidisciplinary body weight reduction program on cardiorespiratory fitness, body composition, and substrate oxidation rate in adolescents with obesity

This study aimed to investigate the effects of combined training (COMB, a combination of moderate-intensity continuous training-MICT and high-intensity interval training-HIIT) vs. continuous MICT administered during a 3-week in-hospital body weight reduction program (BWRP) on body composition, physical capacities, and substrate oxidation in adolescents with obesity. The 3-week in-hospital BWRP entailed moderate energy restriction, nutritional education, psychological counseling, and two different protocols of physical exercise. Twenty-one male adolescents with obesity (mean age: 16.1 ± 1.5 years; mean body mass index [BMI] 37.8 ± 4.5 kg m−2) participated in this randomized control trial study (n:10 for COMB, n:11 MICT), attending ~ 30 training sessions. The COMB group performed 3 repetitions of 2 min at 95% of peak oxygen uptake (V′O2 peak) (e.g., HIIT ≤ 20%), followed by 30 min at 60% of V′O2 peak (e.g., MICT ≥ 80%). Body composition, V′O2 peak, basal metabolic rate (BMR), energy expenditure, and substrate oxidation rate were measured during the first week (W0) and at the end of three weeks of training (W3). The two training programs were equivalent in caloric expenditure. At W3, body mass (BM) and fat mass (FM) decreased significantly in both groups, although the decrease in BM was significantly greater in the MICT group than in the COMB group (BM: − 5.0 ± 1.2 vs. − 8.4 ± 1.5, P < 0.05; FM: − 4.3 ± 3.0 vs. − 4.2 ± 1.9 kg, P < 0.05). V′O2 peak increased only in the COMB by a mean of 0.28 ± 0.22 L min−1 (P < 0.05). The maximal fat oxidation rate (MFO) increased only in the COMB group by 0.04 ± 0.03 g min−1 (P < 0.05). COMB training represents a viable alternative to MICT for improving anthropometric characteristics, physical capacities, and MFO in adolescents with obesity during a 3-week in-hospital BWRP.

FRI391 A Metabolomics Analysis Of Moderate Energy Restriction In Healthy Lean Women

Abstract Disclosure: L. Levine: None. K. Overdahl: None. S. Molsberry: None. S. Shekhar: None. A. Jarmusch: None. J.E. Hall: None. Introduction: Metabolomics can elucidate metabolic responses to dietary interventions and has been used in energy restriction studies, primarily in overweight/obese men and women. Although the menstrual cycle affects the metabolome, most dietary intervention studies have not controlled for menstrual cycle phase, nor have they examined the effect of moderate, short-term energy restriction on the metabolic profile of healthy, normal-weight women. Objective: To characterize metabolomic changes in response to a 55% reduction in dietary intake during the early follicular phase of the menstrual cycle. Methods: Study participants included 19 healthy women aged 18-28 years who were of normal BMI and fitness, not restricting nutritional intake and with biochemically confirmed regular ovulatory menstrual cycles. Participants underwent 5-day dietary interventions in the early follicular phase of two menstrual cycles. The first diet consisted of neutral energy availability (NEA; 45 kcal/kg*lean body mass/day) and the second of deficient energy availability (DEA; 20 kcal/kg*lean body mass/day) without changes in macronutrient composition. On the 5th day of each diet, serum was collected at ∼8am following an overnight fast, and immediately before and every 10 minutes for 60 minutes after the consumption of a standardized isocaloric snack at ∼4pm. Untargeted metabolomic profiling was performed using ultra-high performance liquid chromatography/mass spectroscopy. Univariate statistics were performed on all metabolites, using t-tests with Benjamini-Hochberg false discovery rate adjusted p-values to account for multiple testing (p-value ≤ 0.05). Log2-fold change was calculated for all chemical features. Results: At baseline, participants had a weight of 61.9±2.75 kg (mean±SEM), BMI of 23.96±0.69 kg/m2 (mean±SEM), and percent body fat of 28.01±1.61% (mean±SEM). DEA resulted in a 1.25±0.13 kg (mean±SEM) decrease in body weight (p&amp;lt;0.01). While few statistically significant differences were present between fasted NEA and DEA samples, numerous chemical features were significantly upregulated in DEA post-snack samples. Specifically, 11 carnitines, 7 phosphocholines, and 8 fatty acids or fatty acid intermediates exhibited a log2fold change of 0.5 or higher (&amp;gt;40% increase; p ≤ 0.05) in post-snack DEA samples compared to NEA samples. Conclusion: These results strongly suggest that following isocaloric intake, moderate energy restriction in normal-weight, healthy women is associated not only with the use of fat as an energy source, but also with cellular membrane breakdown. Presentation: Friday, June 16, 2023

Exercise training modifies the bone and endocrine response to graded reductions in energy availability in skeletally mature female rodents.

Reductions in energy availability leading to weight loss can induce loss of bone and impact important endocrine regulators of bone integrity. We sought to elucidate whether endurance exercise (EX) can mitigate bone loss observed in sedentary (SED) skeletally mature rodents subjected to graded energy deficits. Female virgin rats (n=84, 5-mo-old; 12/group) were randomized to baseline controls and either sedentary (SED) or exercise (EX) conditions, and within each exercise status to adlib-fed (ADLIB), or moderate (MOD) or severe (SEV) energy restriction diets for 12 weeks. Rats assigned to EX groups performed treadmill running to increase weekly energy expenditure by 10%. MOD-ER-SED, SEV-ER-SED, MOD-ER-EX and SEV-ER-EX were fed modified AIN93M diets with 20%, 40% 10%, and 30% less energy content, respectively, with 100% of all other nutrients provided. Energy availability (EA) was effectively reduced by ~14% and ~30% in the MOD-ER and SEV-ER groups, respectively. MOD-ER for 12 weeks resulted in few negative impacts on bone and, except for serum leptin in MOD-ER-SED rats, no significant changes in endocrine factors. By contrast, SEV-ER in SED rats resulted in significantly lower total body and femoral neck bone mass, and reduced serum estradiol, IGF-1 and leptin. EX rats experiencing the same reduction in energy availability as SEV-ER-SED exhibited higher total body mass, lean mass, total BMC, and higher serum IGF-1 at the end of 12 weeks. Bone mechanical properties at 3 bone sites (mid-femur, distal femur, femoral neck) were minimally impacted by ER but positively affected by EX. These findings indicate that combining increased EX energy expenditure with smaller reductions in energy intake to achieve a targeted reduction in EA provides some protection against loss of bone mass and lean mass in skeletally mature female rats, likely due to better preservation of circulating IGF-1, and that bone mechanical integrity is not significantly degraded with either moderate or severe reduced EA.

Short-Term Moderate Energy Restriction Does Not Affect Indicators of Oxidative Stress and Genotoxicity in Humans

Restriction of energy intake (ER), without malnutrition of essential nutrients, has repeatedly been demonstrated to increase longevity in rodents. In the antioxidant theory of aging the lack of balance between the generation of free radicals and free radical scavenging was thought to be a main causal agent in the aging process. From this point of view the antiaging effect induced by ER might be due to the lower rate of free-radical production and related damage induced by a lower metabolic rate. The antiaging effects of ER might also occur in humans. This study explored the effects of a 10-week moderately energy-restricted diet (80% of habitual) in 24 non-obese middle-aged men (16 ER subjects, 8 controls) on resting metabolic rate (RMR) and indicators of the primary antioxidant defense system, oxidative stress and genotoxicity. RMR decreased significantly in both groups, even when adjustments were made for the change in body composition. The increase in blood vitamin C concentrations correlated with the increase in urinary 8-hydroxy-deoxyguanosine (80HdG) excretion. The change in urinary 80HdG excretion also correlated with the change in RMR per kg fat-free mass. No differences between groups were found for changes in indicators of genotoxicity, erythrocyte catalase, glutathione peroxidase and superoxide dismutase activity and in plasma vitamin E, A or β-carotene concentrations. We conclude that 10 weeks of moderate ER did not affect indicators of antioxidative capacity, oxidative stress and genotoxicity of humans. Since subjects were not in energy balance at the end of the study, no conclusions can be made with respect to long-term effects.

RF10 | PMON215 Greater changes in metabolic hormones are associated with a smaller decrease in pulsatile LH secretion in response to short term moderate energy restriction in healthy, young women

Abstract Background Energy restriction may result in hypothalamic amenorrhea by inhibiting GnRH secretion and downstream pulsatile LH secretion. Energy restriction also leads to adaptive changes in metabolic hormones. We sought to determine whether metabolic changes in response to energy restriction predict or mitigate inhibition of GnRH secretion. Methods Nineteen healthy women, (mean age ± SD; 23.36 ± 2.08 yrs) with regular ovulatory cycles and no evidence of energy restriction or excessive exercise, underwent two 5-day dietary interventions with identical exercise in the early follicular phase of two menstrual cycles. A neutral energy availability (NEA; 45 kCal/kg*LBM/d) was followed by a deficient energy availability (DEA; 20 kCal/kg*LBM/d) diet. On day five of each intervention, body composition was analyzed (BodPod®), and blood was sampled between 0800 —1600 hours for LH, TSH and GH, every 10 min, cortisol every 30 min, T3, reverse T3 (rT3) and T4 every 60 min, free T3 (FT3), free T4 (FT4) and TBG at 0800 h and 1600 h. We correlated means of pulsatile LH pulse frequency (LHPF) with integrated metabolic hormone changes across the day in the subset of women with reduced or unchanged LHPF after DEA (n=10) using linear regression. Results In ∼50% of healthy young women, LHPF decreased or was unchanged in response to short-term moderate energy deprivation. BMI and bodyweight declined after DEA in both groups while % fat mass was unchanged. TSH, T3, leptin, insulin declined, and T4 increased from NEA to DEA while glucose, cortisol and GH were unchanged. In subjects with reduced/unchanged LHPF, % delta T3 correlated inversely with delta LHPF (r=-0.727, p=0.017). Similarly, non-fasting delta TSH correlated inversely with % delta LHPF (r=-0.643, p=0.045), and % delta AUC TSH (r=-0.642, p=0.045) correlated inversely with DEA LHPF. Percent delta insulin (r= -0.722, p=0.018) and % delta insulin AUC (r= – 0.688, p=0.028) correlated inversely with delta LHPF. Percent delta insulin-glucose ratio (r=-0.772, p=0.009) and % change in AUC insulin-glucose ratio (r=-0.759, p=0.011) also correlated inversely with delta LHPF. This inverse relationship was preserved when insulin was normalized for caloric intake (n-insulin) was correlated with % delta LHPF (r=-0.722, p=0.018) and % delta AUC n-insulin correlated with delta LHPF (r= -0.631 and p= 0.050). Delta AUC leptin (r=-0.684, p=0.029) and % delta AUC leptin (r=-0.670, p=0.034) also correlated inversely with delta LHPF. Mean cortisol at NEA correlated inversely with LHPF during DEA (r=-0.816, p=0.007), implying that higher baseline cortisol levels may predict a greater relative fall in LHPF. Cortisol AUC in DEA also correlated inversely with LHPF in DEA (r=-0.722, p=0.028). Conclusion Our data suggest that greater changes in metabolic hormones may protect against the inhibitory effect of moderate energy deprivation on GnRH secretion in healthy young women with normal reproductive function. Presentation: Saturday, June 11, 2022 1:30 p.m. - 1:35 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

The effect of moderate energy and protein restriction during gilt development on changes in body weight and backfat depth and subsequent lactation performance.

Eighty-eight gilts [initial body weight (BW) 49.8 ± 0.8 kg] were recruited to determine the effects of moderate energy and protein restriction during the development period on changes in BW and backfat depth (BF) and subsequent lactation performance. Gilts were randomly assigned to one of four feeding programs: 1) standard commercial diet fed ad libitum (CON), 2) standard commercial diet fed 10% or 3) 20% below ad libitum, or 4) a high-fiber diet fed ad libitum [2.5 times more fiber (neutral detergent fiber) than the commercial diet to dilute net energy and crude protein by approximately 20% and 13%, respectively; FIB]. The gilts were housed individually and received the feeding programs between 90 and 190 (breeding) d of age and standard gestation and lactation diets thereafter. Litters were standardized to 12 ± 1 pigs within 48 h of farrowing; weaning occurred at 20.0 ± 0.4 d of age. Gilts that received the 20% restricted program had lower overall average daily feed intake (ADFI) during the development period (2.64 ± 0.04 kg; P < 0.05) versus all other feeding programs and gilts that received the 10% restricted program had lower ADFI than FIB and CON, which were not different (2.96 vs. 3.44 and 3.47 ± 0.04 kg for 10%, FIB and CON, respectively; P < 0.05). Plasma free fatty acid (FFA) concentrations on day 180 of age were lower for gilts that received the 10% and 20% restricted programs compared to gilts that received the FIB and CON programs, which were not different (97 and 86 vs. 220 and 149 ± 29 µEq/L, respectively; P < 0.05). Plasma concentrations of glucose, urea, prolactin, and IGF-1 were not different among feeding programs on day 180 of age. At breeding, gilts that received the FIB and 10% programs had lower BW and BF versus CON (145.7 and 144.8 vs. 155.2 ± 0.9 kg and 14.4 and 14.8 vs. 16.5 ± 0.2 mm for BW and BF, respectively; P < 0.05) but greater BW than gilts that received the 20% restricted program (137.9 kg; P < 0.05). The BW and BF of gilts did not differ at the end of gestation or at weaning. The ADFI of sows during lactation and offspring birth weight and growth rate during lactation and the 5-wk nursery period were not influenced by gilt development feeding program. Therefore, a high-fiber feeding program could be used in group-housing gilt-development scenarios, where feed is offered ad libitum, to control BW and BF prior to breeding without influencing milk production in the subsequent lactation period.

Refeeding ewes ad libitum after a moderate energy restriction during mid gestation did not affect the onset of breeding and ovulating rate of female offspring

Sub-nutrition during pregnancy might affect the offspring´s reproductive performance through effects on the development and function of gonads. This study evaluated a maternal energy restriction in ewes from day 48–106 of gestation, on pre- and post-weaning female lambs` performance, onset of female lambs’ breeding and ovulation rate during their first breeding season. Adult Polwarth ewes sired by Finnish rams bearing single or twin lambs were assigned to two dietary treatments from day 48 to day 106 of gestation: restricted (R; n = 60) at 60 % of their metabolizable energy (ME) requirements, or non-restricted (NR; n = 54) at 100 % of their ME requirements. After the restriction period, ewes grazed all together ad libitum until weaning. The ewe lambs were evaluated from birth to weaning, as well as during their first breeding season. Although NR ewes weighed 17.7 % more than R ewes (P < 0.05) at the end of the restriction period, the nutritional treatment of the dams had no effect on the weight of the ewe lambs at birth, weaning or final weight (P > 0.05). Fat depth, rib eye area, the percentage of ewe-lambs cycling and their ovulation rate during the first breeding season was not affected by the ewe´s dietary treatment. Ewes restricted at 60 % of their ME requirements in mid-gestation seemed to have the capacity to compensate any detrimental effects on growth and development as well as the reproductive potential of female lambs if adequate refeeding conditions are provided in late gestation, throughout lactation and post-weaning.

Effect of severe compared with moderate energy restriction on physical activity among postmenopausal female adults with obesity: a prespecified secondary analysis of the Type of Energy Manipulation for Promoting optimum metabolic health and body composition in Obesity (TEMPO) Diet randomized controlled Trial

ABSTRACTBackgroundAn under-explored strategy for increasing physical activity is the dietary treatment of obesity, but empirical evidence is lacking.ObjectivesWe aimed to compare the effects of weight loss via severe as opposed to moderate energy restriction on physical activity over 36 mo.MethodsA total of 101 postmenopausal female adults (45–65 y, BMI 30–40 kg/m2, <180 min/wk of structured exercise) were randomly assigned to either 12 mo of moderate energy restriction (25%–35% of energy requirement) with a food-based diet, or a severe intervention involving 4 mo of severe energy restriction (65%–75% of energy requirement) with a total meal replacement diet, followed by 8 mo of moderate energy restriction. Physical activity was encouraged, but no tailored or supervised exercise prescription was provided. Physical activity was assessed with an accelerometer worn for 7 d before baseline (0 mo) and 0.25, 1, 4, 6, 12, 24, and 36 mo after intervention commencement.ResultsCompared with the moderate group, the severe group exhibited greater mean: total volume of physical activity; duration of moderate-to-vigorous-intensity physical activity (MVPA); duration of light-intensity physical activity; step counts, as well as lower mean duration of sedentary time. All these differences (except step counts) were apparent at 6 mo [e.g., 1006 metabolic equivalent of task (MET)-min/wk; 95% CI: 564, 1449 MET-min/wk for total volume of physical activity], and some were also apparent at 4 and/or 12 mo. There were no differences between groups in the 2 other outcomes investigated (self-efficacy to regulate exercise; and proportion of participants meeting the WHO's 2020 Physical Activity Guidelines for MVPA). When the analyses were adjusted for weight at each time point, the differences between groups were either attenuated or abolished.ConclusionsAmong female adults with obesity, including a dietary component to reduce excess body weight—notably one involving severe energy restriction—could potentially enhance the effectiveness of physical activity interventions.This trial was registered at www.anzctr.org.au as ACTRN12612000651886.

Effects of a 3-Week Inpatient Multidisciplinary Body Weight Reduction Program on Body Composition and Physical Capabilities in Adolescents and Adults With Obesity.

BackgroundThe aim of the present study was to examine the short-term changes in body composition and physical capabilities in subjects with obesity during a multidisciplinary inpatient body weight reduction program (BWRP).MethodsOne hundred thirty-nine adolescents (56 boys and 83 girls; BMI: 37.1 ± 6.5 kg/m2; Fat Mass, FM: 45.3 ± 7.2%) and 71 adults (27 males and 44 females; BMI: 44 ± 4.7 kg/m2; FM: 51.4 ± 4.7%) followed a 3-week inpatient BWRP consisting of regular physical activity, moderate energy restriction, nutritional education and psychological counseling. Before (T0) and after the end of the BWRP (T21), body composition was assessed with an impedancemeter, lower limb muscle power with Margaria Stair Climbing Test (SCT), lower limb functionality with Short Physical Performance Battery (SPPB), and the capacity of performing activity of daily living (ADL) with Physical Performance Test (PPT).ResultsAt T21, obese adolescents showed a 4% reduction in body mass (BM) (p < 0.001), associated with a FM reduction in boys (−10%) and girls (−6%) (p < 0.001) and with a 3% reduction in fat-free mass (FFM) recorded only in boys (p = 0.013). Obese adults showed a 5% BM reduction (p < 0.001), associated with a 2% FFM and 9% FM reduction (p < 0.001) in males, and 7% FM reduction in females (p < 0.001). Regarding physical capabilities, at T21 in obese adolescents, PPT score increased by 4% (p < 0.001), SCT decreased by −5% (boys) and −7% (girls) (p < 0.001), while SPPB score did not change significantly. In obese adults at T21, PPT score increased by 9% (p < 0.001), SCT decreased by −16% (p < 0.001) only in females, and SPPB score increased by 7% (males) and 10% (females) (p < 0.01).ConclusionIn conclusion, moderate energy restriction and regular physical activity determine a 4-5% BM reduction during a 3-week inpatient BWRP, improve physical capabilities and induce beneficial changes in body composition in adolescents and adults with obesity.Trial registrationThis study was approved by the Ethical Committee of the Istituto Auxologico Italiano (Milan, Italy; research code: 01C124; acronym: PRORIPONATFIS). Registered 11 November 2020 - Retrospectively registered.

Energy cost of walking and body composition changes during a 9-month multidisciplinary weight reduction program and 4-month follow-up in adolescents with obesity.

The purpose of the present study was to investigate changes in the energy cost of locomotion during walking (Cw) related to changes in body mass (BM, kg) and body composition in adolescents with obesity. Twenty-six (12 boys and 14 girls) obese adolescents (mean: body mass index, 33.6± 3.7kg·m-2; 42.7± 4.5% fat mass (FM)) followed a 9-month multidisciplinary inpatient weight-reduction program consisting of lifestyle education, moderate energy restriction, and regular physical activity in a specialised institution. At baseline (M0), the end of the 9-month program (M9), and after the 4-month follow-up (M13), oxygen consumption and carbon dioxide production of the standardised activity program were assessed by whole-body indirect calorimetry over 24hours, and body composition was assessed by dual-energy X-ray absorptiometry. At M9, adolescents showed an 18% reduction in BM (p< 0.001) and 40% in total FM, while fat-free mass (kg) remained stable in boys but decreased by ∼6% in girls (p= 0.001). Similarly, the mean Cw decreased by 20% (p< 0.001). At M13, BM, FM, and Cw were slightly higher compared with at M9. In conclusion, moderate energy restriction and regular moderate physical activities improved walking economy, improved exercise tolerance, and induced beneficial changes in the body composition of adolescents with obesity. Novelty: Reduction of FM in the trunk region, and consequently reducing the work carried out by respiratory muscles, contributes to reducing Cw in adolescents with obesity. A lower walking cost can be effective in improving exercise tolerance and quality of life in obese adolescents.

Effects of Energy-Restricted Feeding during Rearing on the Performance, Uniformity, and Development of Rugao Layer Breeders at the Initiation of the Laying Period.

Simple SummaryThree major factors affecting productive performance of laying hens are BW, flock uniformity, and GIT development at the initiation of the laying period. Various feeding management practices to restrict feed intake of broiler breeders during the rearing phase to optimize BW for reproductive performance can improve BW uniformity. Hence, the feed restriction methods used for broiler breeders might be used to improve flock uniformity and the GIT development of laying hens. The objective of the study was to investigate the effects of energy-restricted feeding and switching to ad libitum feeding on the performance, uniformity, and development of Rugao layer breeders at the initiation of the laying period. Moderate energy restriction from 8 to 18 weeks of age and switching to ad libitum feeding can stimulate the development of the GIT and improve BW uniformity of layer breeders. Improved ECR was observed overall in the experiment. In addition, the BW of layer breeders recovered after the pullets were switched to ad libitum feeding for 3 weeks. These results provide a theoretical basis for the application of energy-restricted feeding in young layer breeders, which may have important practical importance for layer breeders because a better rearing cycle can be advantageous to production performance.The aim of this study was to assess the effects of energy-restricted feeding during rearing on the performance, uniformity, and development of layer breeders at the initiation of the laying period. A total of 2400 8-week-old Rugao layer breeders were randomly assigned to one of five groups (480 pullets per group) with eight replicates and were fed one of five diets that were nutritionally equal with the exception of apparent metabolizable energy corrected for nitrogen (AMEn) content (2850, 2750, 2650, 2550, and 2450 kcal AMEn/kg) from 8 to 18 weeks of age. The daily amount of feed was restricted to the absolute quantity of the diet consumed by laying hens fed 2850 kcal AMEn per kg diet ad libitum (control). From 18 to 21 weeks of age, all hens were fed a basal diet ad libitum. The body weight (BW) of the laying pullets decreased linearly with increasing energy restriction (p < 0.001) but recovered within 3 weeks of ad libitum feeding (p = 0.290). A gradual increase in the degree of energy restriction resulted in a gradual decrease in average daily weight gain (ADG) and a gradual increase in the feed conversion ratio (FCR) and energy conversion ratio (ECR) from 8 to 18 weeks of age (p < 0.001, p < 0.001, p = 0.008). In contrast, the ADG and ADFI (p < 0.001, p < 0.001) gradually increased, while the FCR and ECR (p < 0.001, p < 0.001) gradually improved from 18 to 21 weeks of age. From 8 to 21 weeks of age, ECR improved (p = 0.005) with an increasing degree of energy restriction. The energy-restricted feeding for 6 weeks to the end of the trial improved BW uniformity (p < 0.05). The relative length and circumference of tarsus (p < 0.001, p < 0.001), and the relative weights and lengths of the small intestine, duodenum, jejunum, ileum, and caeca increased linearly (p < 0.001, p = 0.012, p < 0.007, p = 0.012, p = 0.040; p < 0.001, p = 0.003, p = 0.032, p = 0.029, p = 0.040) with increasing energy restriction at 18 weeks of age. After switching to ad libitum feeding for 3 weeks, the relative weights and lengths of the small intestine, duodenum, and jejunum of laying pullets increased linearly with increasing energy restriction (p < 0.001, p = 0.016, p = 0.011; p = 0.009, p = 0.028, p = 0.032). In conclusion, moderate energy restriction (85.97%, 2450 vs. 2850 kcal AMEn/kg) from 8 to 18 weeks of age and switching to ad libitum feeding from 18 to 21 weeks of age can be used to improve BW uniformity and stimulate the development of the duodenum and jejunum of native layer breeders at the initiation of the laying period without compromising BW.

High-Protein Energy-Restriction: Effects on Body Composition, Contractile Properties, Mood, and Sleep in Active Young College Students.

Background: It is often advised to ensure a high-protein intake during energy-restricted diets. However, it is unclear whether a high-protein intake is able to maintain muscle mass and contractility in the absence of resistance training.Materials and Methods: After 1 week of body mass maintenance (45 kcal/kg), 28 male college students not performing resistance training were randomized to either the energy-restricted (ER, 30 kcal/kg, n = 14) or the eucaloric control group (CG, 45 kcal/kg, n = 14) for 6 weeks. Both groups had their protein intake matched at 2.8 g/kg fat-free-mass and continued their habitual training throughout the study. Body composition was assessed weekly using multifrequency bioelectrical impedance analysis. Contractile properties of the m. rectus femoris were examined with Tensiomyography and MyotonPRO at weeks 1, 3, and 5 along with sleep (PSQI) and mood (POMS).Results: The ER group revealed greater reductions in body mass (Δ −3.22 kg vs. Δ 1.90 kg, p < 0.001, partial η2 = 0.360), lean body mass (Δ −1.49 kg vs. Δ 0.68 kg, p < 0.001, partial η2 = 0.152), body cell mass (Δ −0.85 kg vs. Δ 0.59 kg, p < 0.001, partial η2 = 0.181), intracellular water (Δ −0.58 l vs. Δ 0.55 l, p < 0.001, partial η2 = 0.445) and body fat percentage (Δ −1.74% vs. Δ 1.22%, p < 0.001, partial η2 = 433) compared to the CG. Contractile properties, sleep onset, sleep duration as well as depression, fatigue and hostility did not change (p > 0.05). The PSQI score (Δ −1.43 vs. Δ −0.64, p = 0.006, partial η2 = 0.176) and vigor (Δ −2.79 vs. Δ −4.71, p = 0.040, partial η2 = 0.116) decreased significantly in the ER group and the CG, respectively.Discussion: The present data show that a high-protein intake alone was not able to prevent lean mass loss associated with a 6-week moderate energy restriction in college students. Notably, it is unknown whether protein intake at 2.8 g/kg fat-free-mass prevented larger decreases in lean body mass. Muscle contractility was not negatively altered by this form of energy restriction. Sleep quality improved in both groups. Whether these advantages are due to the high-protein intake cannot be clarified and warrants further study. Although vigor was negatively affected in both groups, other mood parameters did not change.

Effects of energy-restricted feeding during rearing on sexual maturation and reproductive performance of Rugao layer breeders

The aim of this study was to assess the effects of energy-restricted feeding during rearing on the sexual maturation and reproductive performance of Rugao layer breeders. A total of 2,400 8-wk-old Rugao layer breeders were randomly assigned to one of 5 groups (480 pullets per group) with eight replicates and were fed one of 5 diets that were nutritionally similar with the exception of apparent metabolizable energy corrected for nitrogen (AMEn) content (2,850, 2,750, 2,650, 2,550, and 2,450 kcal AMEn/kg) from 8 to 18 wks of age. The daily amount of feed was restricted to the absolute quantity of the diet consumed by laying hens fed 2,850 kcal AMEn per kg diet ad libitum (control). From 18 to 52 wks of age, all hens were fed basal diets ad libitum. The body weight of layer breeders at 18 wks of age decreased linearly with increasing energy restriction (P < 0.001), but caught up within 3 wks of ad libitum feeding (P = 0.290). The coefficient of variation of the body weight of the hens at 18, 21, and 24 wks of age decreased linearly (P = 0.010, 0.025, and 0.041, respectively) with increasing energy restriction during rearing. Energy-restricted feeding delayed sexual organ development at 18, 20, and 22 wks of age, including the number of large yellow follicles, oviduct length, oviduct length index, oviduct index, and ovary stroma index (P < 0.05), and delayed sexual maturity, including the age at laying the first egg and the age at 5% and 50% egg production (P = 0.042, 0.004, and 0.029, respectively). Consequently, egg number from 5% to 50% egg production decreased linearly as the degree of energy restriction increased (P = 0.001) and egg production of hens in the energy-restricted feeding groups was lower than that of hens in the ad libitum feeding group (6.36, 6.43, 6.4, and 4.61% vs. 14.29%; P < 0.05) from 18 to 20 wks of age. Furthermore, egg weight increased linearly as energy restriction increased (P < 0.001) and laying hens in the most severe energy-restricted feeding group had more setting eggs (normal eggs weighing >40 g) than hens in the ad libitum feeding and lighter energy-restricted feeding groups (149.57 vs. 144.34, 142.66, 143.63, and 141.78; P < 0.05). No significant differences were observed in fertility, hatchability of fertile eggs, and hatchability of setting eggs (P = 0.381, 0.790, and 0.605, respectively). In conclusion, moderate energy restriction (85.97%, 2,450 vs. 2,850 kcal AMEn/kg) from 8 to 18 wks of age increased egg weight as well as the production of setting eggs in native layer breeders throughout the laying period, without adverse effects on productive performance from 18 to 52 wks of age, or fertility and hatchability at 52 wks of age.

Carbohydrate refeed does not modify GVT-performance following energy restriction in bodybuilders.

Bodybuilding is a sport in which competitors' physiques are judged on their muscular size, symmetry, and leanness, as displayed in a number of different poses. In the pre-competitive period, bodybuilders attempt to reduce body fat stores as much as possible while maintaining fat-free mass (FFM). This is achieved via a sustained negative energy balance, generally induced by a combination of decreased energy intake and increased energy expenditure. This study aimed to assess the ability of bodybuilders to resist fatigue during resistance exercise based German Volume Training (GVT), as well as the affective response after carbohydrate refeed following four weeks of moderate or severe energy restriction. Eleven male bodybuilders (28.4±2.3 years old) with experience in competitions were randomized into two groups: Moderate Energy Restriction (MER; n=6) or Severe Energy Restriction (SER; n=5). On the 2nd day (during energy restriction) and 7th day (during refeed) of the fourth week, both groups completed two leg press protocols involving the GVT method. After the first and last workout protocol subjects were assessed for muscle soreness using the visual-analog scale (VAS), rating of perceived exertion (RPE), affective response, lactate, and creatine kinase. Anthropometric analysis indicated that a reduction of 3.7 and 3.2% in body mass corresponded to a loss of 16.0 and 17.6% of fat mass for the MER and SER groups, respectively, with both groups maintaining FFM. Blood CK and VAS values were reduced only in SER. Our results suggest that a carbohydrate refeed may help to attenuate the perception of muscle soreness and maintain exercise performance, especially when severe energy restriction is combined with an intense training protocol such as GVT.

Effect of Different Levels of Energy Diet Restriction on Energy Balance, Leptin and CL Development, Vascularization, and Function in South American Camelids.

The objective was to determine the effect of energy diet restriction on energy balance, systemic leptin and corpus luteum (CL) vascularization, development, and function in South American camelids. In experiment 1, adult llamas were randomly assigned to receive a diet of 70% of their maintenance energy requirements (MER) (Restricted group, n = 7) or fed ad libitum (Control group, n = 7) during 28 days. Body live weight (BLW) and body condition score (BCS) were recorded, blood samples were collected every 2 weeks to measure plasma leptin concentrations, and energy metabolites were quantified. In experiment 2, adult alpacas were randomly assigned to receive a diet of 40% MER for 21 days (Restricted group, n = 7) or fed ad libitum (Control group, n = 7). Then, ovulation was induced with gonadorelin acetate (day = 0), and trans-rectal ultrasonography (7.5 MHz) was performed using B and Doppler mode to record the diameter of the pre-ovulatory follicle, ovulation, CL diameter, and vascularization from Days 0 to 13. Blood samples were collected every 48 h from Days 1 to 13 to quantify plasma leptin and progesterone concentrations. In experiment 1, energy diet restriction of 70% MER did not affect plasma leptin concentration and metabolic parameters of the Restricted group. In experiment 2, the Restricted group had a lower BCS (p < 0.001), a smaller diameter of the CL on Days 5 and 7 (p < 0.05), and a smaller maximum diameter of the CL (10.2 ± 0.6 mm) than the Control group (12.1 ± 0.6 mm; p = 0.04). Low energy restriction of 70% MER for 28 days did not affect the energy balance of llamas (Experiment 1). Moderate energy restriction of 40% MER for 21 days negatively affected energy balance (BCS), and CL development but not its vascularization, leptin, and progesterone concentrations. These species must be submitted to longer periods or a higher level of energy restriction to impair ovarian function.

Exploring the highs and lows of very low carbohydrate high fat diets on weight loss and diabetes‐ and cardiovascular disease‐related risk markers: A systematic review

AbstractAimVery low carbohydrate high fat diets (VLCHF) are increasingly popular for weight loss and diabetes management, but the risk implications of long‐term adherence to a high‐fat‐diet remain unclear, especially in high‐risk populations. This review aimed to examine adherence, weight loss, diabetes‐ and cardiovascular disease (CVD)‐related risk markers in adults consuming VLCHF diets.MethodsOnline databases were searched for randomised controlled trials ≥3 months duration that met a pre‐defined macronutrient prescription: VLCHF ≤25%E carbohydrate, &gt;35%E fat; low fat (LF) ≥45%E carbohydrate, ≤30%E fat; and reported energy, saturated fat (SFA), weight, blood glucose, cholesterol and blood pressure (BP). Studies were excluded if the macronutrient prescription was not targeted (n = 32); not met (n = 17) or not reported (n = 13).ResultsEight studies included: 1217 commenced; 922 completed overweight and obese adults. Diets were isocaloric moderately energy‐restricted, closely monitored with ongoing support from dietitians, physicians, and/or nurses. Four studies reported non‐adherence beyond 3 months (n = 3) and 6 months (n = 1) despite interventions of 12, 15 and 24 months. VLCHF diets were high in fat and SFA (fat 49%‐56%E; SFA 11%‐21%E) compared to LF diets (fat 13%‐29%E; SFA 5%‐11%E). All groups achieved significant weight loss and improvements in BP and blood glucose. LDL‐C reduction favoured LF, P &lt; .05; increased HDL‐C and reduced triglyceride levels favoured VLCHF, P &lt; .05.ConclusionsVLCHF and LF diets with moderate energy restriction demonstrate similar weight loss and improvements to BP to 3 months. However, adherence is likely poor without intensive support from health professionals. Dietary SFA should be monitored to ensure recommended intakes, but longer‐term studies with high adherence are required to confirm the level of CVD‐risk and potential harms.

The Effect Of Continuous Energy Restriction Vs Intermittent Fasting, With Resistance Training, On Lean Mass

PURPOSE: To determine if two energy restricted diets (continuous energy restriction (CER) and 5:2 intermittent fasting (IF)) combined with resistance training (RT) results in lean body mass (LBM) retention while reducing bodyweight. METHODS: Thirty-four young, untrained males and females were randomised to undertake the following diets for 12 weeks: CER (consume 80% of estimated energy requirements (EER) every day), or IF (consume approximately 30% of EER twice per week on fast days and 100% of EER every other day). Fast days included meals of protein shakes, a soup and vegetables. Both groups aimed to be isocaloric with an average energy restriction of 20% EER, and isonitrogenous consuming an average protein intake of 1.5 grams per kilogram of bodyweight per day. Both groups completed 2 supervised RT sessions and 1 unsupervised workout per week. The IF group completed their exercise on non-fast days. Body composition was assessed by dual x-ray absorptiometry. Data was analysed using an intention-to-treat linear mixed model, assuming AR(1) dependence across time. In addition, a change analysis was conducted for participants who completed both the baseline and 12 week assessments. RESULTS: For females, bodyweight was significantly reduced (mean decrease 3.1%, p=0.009), and LBM significantly increased (mean increase 5.8%, p<0.001), with no difference observed between diets. Similarly for men, there was no significant diet effect on bodyweight; both groups experienced an overall reduction of 6.3% (p<0.001). Combined, men in both diet groups experienced a significant increase in LBM (mean increase 1.4%, p=0.021), however there was a trend towards a greater increase in LBM in the IF compared to the CER group (mean increase CER = 0.7%, IF = 2.0%). CONCLUSIONS: Across both diet groups, males and females experienced a significant reduction in bodyweight while, on average, increasing LBM. Neither diet was more effective for bodyweight reduction, however there was a trend towards greater LBM accrual in IF compared to CER males. Gender specific responses to the intervention were evident, with a greater increase in LBM for females. Moderate energy restriction with high protein intake and RT can lead to concomitant weight loss and LBM accrual.

3-Year effect of weight loss via severe versus moderate energy restriction on body composition among postmenopausal women with obesity - the TEMPO Diet Trial

We have previously shown that a severely energy-restricted diet leads to greater loss of weight, fat, lean mass and bone mineral density (BMD) at 12 months in postmenopausal women with obesity than a moderately energy-restricted diet. We now aim to evaluate whether these effects are sustained longer term (ie, at 36 months). 101 postmenopausal women were randomized to either 12 months of moderate (25 to 35%) energy restriction with a food-based diet (moderate intervention), or 4 months of severe (65 to 75%) energy restriction with a total meal replacement diet followed by moderate energy restriction for 8 months (severe intervention). Body weight and composition were measured at 0, 24 and 36 months. Participants in the severe intervention lost ~1.5 to 1.7 times as much weight, waist circumference, whole-body fat mass and visceral adipose tissue compared to those in the moderate intervention, and were 2.6 times more likely (42% versus 16%) to have lost 10% or more of their initial body weight at 36 months (P < 0.01 for all). However, those in the severe versus moderate intervention lost ~1.4 times as much whole-body lean mass (P < 0.01), albeit this was proportional to total weight lost and there was no greater loss of handgrip strength, and they also lost ~2 times as much total hip BMD between 0 and 36 months (P < 0.05), with this bone loss occurring in the first 12 months. Thus, severe energy restriction is more effective than moderate energy restriction for reducing weight and adiposity in postmenopausal women in the long term (3 years), but attention to BMD loss in the first year is required. Trial registrationAustralian New Zealand Clinical Trials Registry Reference Number: 12612000651886, anzctr.org.au.

Adults Consuming an Energy-Restricted US Healthy-Style Eating Pattern at Either the Recommended or a Higher Protein Quantity Perceive a Shift from “Poor” to “Good” Sleep

Abstract Objectives Limited evidence from secondary analyses suggests consuming a higher protein diet during weight loss improves subjective indices of sleep in adults who are overweight and obese. We sought to a priori assess the effects consuming a U.S. Healthy–Style Eating Pattern with the recommended versus a higher amount of protein and moderate energy-restriction on sleep quality indices. Methods Using of a randomized, parallel-design, 51 men and women (mean ± SEM; age: 47 ± 1 y; BMI: 32.6 ± 0.5 kg/m2) consumed a controlled U.S. Healthy-Style Eating Pattern containing 750 kcal/d less than their estimated energy requirement for 12 wk. The additional dietary protein (7.5 oz-eq/d) came from animal-based protein sources and displaced primarily whole and reined grains. Objective and subjective sleep quality indices were measured using wrist-worn actigraphy and questionnaires (Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale), respectively, at pre-, mid- (week 6), and post-intervention (week 12). Results Among all participants, body mass decreased (-6.2 ± 0.4 kg). Dietary protein intake did not affect any of the objective or subjective sleep quality outcomes measured. Over time, objective measures of time spend in bed, time spent sleeping, sleep efficiency, sleep onset latency, and time awake after sleep onset did not change. Subjective measures of global sleep score (GSS, −3.8 ±0.4 au) and daytime sleepiness score (−3.8 ± 0.4 au; both P &amp;lt; 0.001) improved over time. The GSS improvement transitioned the group of participants from being categorized with a poor to a good sleep condition (GSS &amp;gt;5 versus ≤5 au of 0–21 au scale; Pre 7.9 ± 0.5 au, Post: 4.0 ± 0.6 au). Conclusions Although objective sleep quality may not improve, adults with poor sleep may perceive becoming good sleepers while consuming a moderately energy-restricted U.S. Healthy-Style Eating Pattern containing either the recommended or a higher amount of protein. Funding Sources The Beef Checkoff and American Egg Board-Egg Nutrition Center.