Percentage Of Daily Energy Intake Research Articles

A Systematic Review, Meta-Analysis and Meta-Regression on the Effects of Carbohydrates on Sleep.

This study aimed to assess the effects of quantity, quality and periodization of carbohydrates consumption on sleep. PubMed, SCOPUS and Cochrane Library were searched through October 2020. Data were pooled using random-effects meta-analysis. Eleven articles were included in the meta-analysis which consisted of 27 separate nutrition trials, resulting in 16 comparison data sets (sleep quantity n = 11; sleep quality n = 5). Compared to high carbohydrate (HCI), low carbohydrate intake (LCI) moderately increased duration and proportion of N3 sleep stage (ES = 0.37; 95% CI = 0.18, 0.56; p < 0.001 and ES = 0.51; 95% CI = 0.33, 0.69; p < 0.001, respectively). HCI prolonged rapid eye movement (REM) stage duration (ES = −0.38; 95% CI = 0.05, −8.05; p < 0.001) and proportion (ES = −0.46; 95% CI = −0.83, −0.01; p < 0.001), compared to LCI. The quality of carbohydrate intake did not affect sleep stages. Meta-regression showed that the effectiveness of carbohydrate quantity and quality in sleep onset latency was significantly explained by alterations of carbohydrate intake as a percentage of daily energy intake (R2 = 25.87, p = 0.018) and alterations in the glycemic load (R2 = 50.8, p = 0.048), respectively. Alterations in glycemic load partially explained the variance of the effectiveness of carbohydrate quality in sleep efficiency (R2 = 89.2, p < 0.001) and wake after sleep onset (R2 = 64.9, p = 0.018). Carbohydrate quantity was shown to affect sleep architecture, and especially N3 and REM sleep stages. Alterations in both quantity and quality of carbohydrate intake showed a significant effect on sleep initiation. Variations in carbohydrate quality significantly affected measures of sleep continuation. Further studies are needed to assess the effect of long-term carbohydrate interventions on sleep.

Influence of Ultra-Processed Foods Consumption on Redox Status and Inflammatory Signaling in Young Celiac Patients.

The current study was designed to assess the influence of consumption of ultra-processed (UPF) on oxidative/antioxidant balance and evoked inflammatory signaling in young patients with celiac disease (CD). The study included 85 children. The celiac group (n = 53) included children with CD with a long (>18 months, n = 17) or recent (<18 months, n = 36) adherence to a gluten-free diet (GFD). The control group (n = 32) included healthy children with a significantly lower consumption of UPF compared to the CD group, both expressed as kcal/day (p = 0.043) and as percentage of daily energy intake (p = 0.023). Among children with CD, the group with the lowest consumption of UPF (below the 50% of daily energy intake) had a greater Mediterranean diet (MD) adherence and higher moderate physical activity levels. In addition, CD children with the lowest consumption of UPF had healthier redox (lower soluble superoxide dismutase-1 and 15-F2t-isoprostanes) and inflammatory profiles (lower macrophage inflammatory protein-1α) compared to the group with the highest consumption of UPF (all, p < 0.05) regardless of the time on a GFD. These findings highlight the importance of a correct monitoring of the GFD. An unbalanced GFD with high consumption of UPF and an unhealthy pattern with less physical activity and worse adherence to MD results in a worse inflammatory profile, which could act as a parallel pathway that could have important consequences on the pathophysiology of the disease.

Correlation Between Daily Energy Intake from Fat with Insulin Resistance in Patients with Polycystic Ovary Syndrome.

ObjectiveThe aim of the present study was to investigate the possible correlation between the percentage of daily energy intake from fat (PEF) with insulin resistance (IR) in women with polycystic ovary syndrome (PCOS).MethodsIn this cross-sectional study, a total of 186 females with PCOS were screened. Daily dietary intake data were collected by a trained nutritionist using the 24-h dietary recall method over three consecutive days. A total of 111 subjects who had complete data were divided into two groups based on the percentage of daily energy intake from fat (PEF): the normal PEF (NPEF) group (PEF < 30%) and the high PEF (HPEF) group (PEF ≥ 30%). Pearson’s correlation analysis and stepwise multivariate linear regression analysis were used to analyze the correlation of PEF with homeostasis model assessment of insulin resistance (HOMA-IR).ResultsThe total prevalence rate of overweight/obesity was 80.2%. There were significant differences in waist circumference (WC), body mass index (BMI), fasting insulin, and HOMA-IR (P < 0.001) among the normal weight, the overweight, and the obese groups, but no significant differences were observed in total energy and dietary macronutrients intake in the three groups. The daily intake of fat and protein, fasting insulin, and HOMA-IR in the NPEF group were significantly higher than those in the HPEF group. Pearson’s correlation analysis showed PEF in PCOS women was negatively correlated with BMI (r= −0.189, p=0.047) and HOMA-IR (log-transformed) (r= −0.217, p=0.022). Further, stepwise multivariate linear regression analysis showed PEF was negatively correlated with HOMA-IR (p<0.05).ConclusionThe percentage of daily energy intake from fat is negatively correlated with IR in women with PCOS.

The Cost of Diets According to Their Caloric Share of Ultraprocessed and Minimally Processed Foods in Belgium.

Background: This study estimated the monetary cost of diets with higher and lower caloric shares of ultraprocessed food products (UPF) and unprocessed/minimally processed foods (MPF) in Belgium for various sociodemographic groups. Methods: Data from the latest nationally representative Food Consumption Survey (FCS) 2014–2015 (n = 3146; 3–64 years) were used. Dietary data were collected through two nonconsecutive 24-hour recalls (food diaries for children). Average prices for >2000 food items (year 2014) were derived from GfK ConsumerScan panel data and linked with foods consumed in the FCS. Foods eaten were categorized by their extent of processing using the NOVA classification. The average caloric share (percentage of daily energy intake) of UPF and MPF were calculated. The mean diet cost was compared across the UPF and MPF contribution tertiles, using linear regression. Results: The average price per 100 kcal for UPF was significantly cheaper (EUR 0.55; 95%CI = 0.45–0.64) than for MPF (EUR 1.29; 95% CI = 1.27–1.31). UPF contributed between 21.9% (female adults) and 29.9% (young boys), while MPF contributed between 29.5% (male adolescents) and 42.3% (female adults) to the daily dietary cost. The contribution of MPF to the daily dietary cost was significantly higher for individuals with a higher household education level compared to those with a lower household education level (p < 0.01). Adjusted for covariates, the average dietary cost per 2000 kcal was significantly lower for individuals in the highest compared to the lowest tertile for the proportion of daily energy consumed from UPF (EUR −0.37 ± 0.13; p = 0.006), and significantly higher for individuals in the highest compared to the lowest tertile for proportion of daily energy consumed from MPF (EUR 1.18 ± 0.12, p < 0.001). Conclusion: Diets with a larger caloric share of UPF were significantly cheaper than those with a lower contribution of these products, while the opposite was found for MPF. Policies that improve relative affordability and accessibility of MPF are recommended.

Consumption of maize food group and its contribution on the diet of rural women in México

AbstractNative maize is the main cereal in the diet in rural communities in México, especially in those with a traditional maize-based food-pattern. Although maize has a high nutritional value, its consumption in rural communities has declined in recent decades. Traditional food replacement by modern and processed foods seems to adversely affect the composition of the diet. The aims of this study were: to evaluate the consumption of maize, its influence on nutrient intake in Matlatzincas women, and to analyze the association between the intake of maize food products with specific nutrients within the context of the most current dietary pattern in this indigenous group from central México. In this longitudinal study, we assessed diet over a one-year period, using eight 24-h dietary recalls and a food frequency questionnaire in a rural representative sample of 92 indigenous women aged 19 to 90 years. We derived dietary patterns using principal component analysis based on the intake of ten predefined food groups according to the Mexican equivalents food system. A specific food group based on maize products (maize-food-group) such as tortilla, sopes, pozole, atole, pinole, tacos, etc., was created to identify separately maize consumption in the habitual diet. The percentage of daily energy intake attributed to maize-food-group as well as the intake of macro and micronutrients were estimated. Based on the nutrimental composition of each food group, we analyzed habitual intakes of energy (kcal/d), carbohydrates, proteins, lipids, fiber, vitamins A, D, C and B12 (mg/d), and micronutrients: phosphorus, calcium, iron and zinc (mg/d). Analysis of variance and Pearsońs correlation test were used to evaluate the association between the tertiles of the consumption of maize-food-group and nutrient intake. Additionally, a diet score was calculated to assess diet quality according to maize-food-group consumption. All dietary data were energy-adjusted for the analysis. The consumption of maize-based-foods corresponded to 23.0% of the total caloric intake. Consumption of maize was higher among older women. Consumption of maize-food-group was positively correlated with the ingest of proteins, lipids, dietary fiber, calcium, phosphorus, iron, B12 vitamin, D vitamin and energy (p &lt; 0.05). Better diet quality was associated with a high consumption of maize-food-group. We conclude that the high consumption of maize food products and its positive correlation with the intake of recommended nutrients for healthy diet in adult women, needs interventions in public health to promote a better diet-quality aimed to increase the intake of maize-based food group.

Relative Validity and Reproducibility of a Food Frequency Questionnaire to Assess Energy Intake from Minimally Processed and Ultra-Processed Foods in Young Children.

NOVA is a food classification system that categorises food items into one of four categories according to the extent and purpose of their processing: minimally processed food (MPF), processed culinary ingredient (PCI), processed food (PF), or ultra-processed food (UPF). The aim of this study was to determine the relative validity and reproducibility of a food frequency questionnaire (EAT5 FFQ) for measuring daily energy intake (EI kJ) and percentage of daily energy intake (EI%) from each NOVA group in New Zealand children. One hundred parents of five year old children completed the 123 item EAT5 FFQ on two occasions four weeks apart. A 3 day weighed diet record (WDR) was completed on non-consecutive randomly assigned days between FFQ appointments. The FFQ overestimated EI (both as kJ and %) from MPF and UPF, and underestimated intakes from PCI and PF, compared with the WDR. Bland–Altman plots indicated reasonably consistent agreement between FFQ and WDR for MPF and UPF but not PCI or PF. Correlation coefficients between the FFQ and WDR were acceptable for EI (%) for MPF (r = 0.31) and UPF (r = 0.30). The FFQ differentiated between the highest and lowest quartiles for EI (%) from MPF and UPF foods (p-values for the trends were 0.006 and 0.009 respectively), and for EI (kJ) from UPF foods (p-value for trend 0.003). Bland–Altman plots indicated consistent agreement between repeat administrations of FFQ for MPF and UPF only, while intra-class correlations suggested good reproducibility for EI (kJ and %) for all four NOVA categories (range 0.51–0.76). The EAT5 FFQ has acceptable relative validity for ranking EI (%) from MPF and UPF. It has good reproducibility for measuring EI from all four NOVA categories, in young children.

Excess nutritional risk in infants and toddlers in a Spanish city.

Adequate dietary intake is vital for infants' growth and development. The aim was to analyse food consumption and energy and nutrient intakes in a group of healthy Spanish infants and toddlers. Cross-sectional study. 154 infants were assessed at 6 months, and followed at 12 and 30 months. Clinical history, anthropometry, type of feeding, food consumption and energy and nutrient intakes (24-hours recall) were estimated. Advice about food consumed, estimated average requirements, the prevalence of inadequate intakes and percentage of adequacy of the recommended dietary allowance were applied. Toddlers had an excessive daily consumption of meat (>51.3g/day), milk (>545g/day), fish (>20.8g/day) and free-sugar foods (>30.5g/day). This consumption was related to a very high intake of proteins (>18%) and free sugars (>10%), at 12 and 30 months, as a percentage of daily energy intake. The mean prevalence of inadequacy intakes was above 48% for iron at 6 months, and 68% and 87% for vitamin D at 12 and 30 months, respectively. At 6 months, infants who were breastfed had greater adequacy in energy and nutrients to recommended dietary, while infants fed infant formula had a higher intake (>120% compared with RDA) in vitamins E, C, B1, B2, pantothenic acid, B6, B12 and folic acid. The contribution of micronutrients in infant formula should be reviewed, appropriate protein and free sugars should be provided during complementary feeding, as well as strategies to avoid vitamin D deficiency since childhood; and continue with the promotion of breastfeeding.

Teens with Type 1 Diabetes: How Does Their Nutrition Measure Up?

Objective To characterize the intake of macronutrient and fiber in adolescents with type 1 diabetes (T1D) and examine their association with health indicators. Methods Baseline data from an RCT were examined. Adolescent-parent dyads (n = 257, mean age 12 ± 1.2 years, 49.4% girls) reported dietary intake via two separate 24-hour recall interviews during a two-week period. Demographic and medical variables were abstracted from questionnaires and medical charts. Results Controlling for demographic and diet variables, a higher percentage of daily energy intake from fats was associated with poorer HbA1c. In contrast, an association between higher percent of energy intake from proteins and carbohydrates was found with higher systolic and diastolic BP, respectively. Conclusions Many early adolescents with T1D did not meet diabetes nutritional guidelines. Lower adherence to nutritional guidelines, specifically more than recommended energy intake from fats, was associated with poorer HbA1c. Addressing nutritional guidelines and increasing adherence as part of treatment may improve health outcomes for youth with T1D.

Impact of Early Initiation of Enteral Nutrition on Survival During Pediatric Extracorporeal Membrane Oxygenation.

Pediatric data related to safety, tolerance, and outcomes of enteral nutrition (EN) for patients requiring extracorporeal membrane oxygenation (ECMO) are lacking. The objectives of this study were to evaluate early nutrition status and timing of EN initiation on survival during pediatric ECMO. A single center institutional review board-approved retrospective chart review was performed on all pediatric patients requiring ECMO from October 2008 through December 2013. Demographics, ECMO variables, laboratory values, vasoactive inotropic score (VIS), and nutrition data on day 5 (d5) were collected. Patients receiving parenteral nutrition (PN) were compared with those receiving any EN on d5. Analyses were conducted to identify factors influencing survival to completion of ECMO and to discharge. Forty-nine patients aged 53 ± 76 months met inclusion criteria. Kaplan-Meier curves demonstrated greater survival to discharge in patients receiving any EN, compared with only receiving PN (P = .031). EN on d5 of ECMO support (P = .040) and a higher percentage of daily energy intake achieved (P = .013) were protective, whereas a higher VIS was associated with increased mortality (P = .010). Multivariable analysis demonstrated EN was no longer associated with survival to discharge (P = .139), whereas energy intake (P = .021) and VIS (P = .013) remained significant. Pediatric patients who received nutrition that was closer to goal energy intake, as well as those who received any EN early during ECMO, had improved survival to hospital discharge.

Sleep Duration and Chronic Fatigue Are Differently Associated with the Dietary Profile of Shift Workers.

Shift work has been associated with dietary changes. This study examined factors associated with the dietary profiles of shift workers from several industries (n = 118, 57 male; age = 43.4 ± 9.9 years) employed on permanent mornings, nights, or rotating 8-h or 12-h shifts. The dietary profile was assessed using a Food Frequency Questionnaire. Shift-related (e.g., sleep duration and fatigue), work-related (e.g., industry), and demographic factors (e.g., BMI) were measured using a modified version of the Standard Shift work Index. Mean daily energy intake was 8628 ± 3161 kJ. As a percentage of daily energy intake, all workers reported lower than recommended levels of carbohydrate (CHO, 45%–65%). Protein was within recommended levels (15%–25%). Permanent night workers were the only group to report higher than recommended fat intake (20%–35%). However, all workers reported higher than recommended levels of saturated fat (>10%) with those on permanent nights reporting significantly higher levels than other groups (Mean = 15.5% ± 3.1%, p < 0.05). Shorter sleep durations and decreased fatigue were associated with higher CHO intake (p ≤ 0.05) whereas increased fatigue and longer sleep durations were associated with higher intake of fat (p ≤ 0.05). Findings demonstrate sleep duration, fatigue, and shift schedule are associated with the dietary profile of shift workers.

The role of infant appetite in extended formula feeding

ObjectiveParental decision-making around extended formula feeding (12 months+) has not been explored previously. This study tested the hypotheses that extended formula milk use (i) is associated with poorer appetite and...

Soda Consumption during Ad Libitum Food Intake Predicts Weight Change

Soda consumption may contribute to weight gain over time. Objective data were used to determine whether soda consumption predicts weight gain or changes in glucose regulation over time. Subjects without diabetes (128 men, 75 women; mean age 34.3±8.9 years; mean body mass index 32.5±7.4; mean percentage body fat 31.6%±8.6%) self-selected their food from an ad libitum vending machine system for 3 days. Mean daily energy intake was calculated from food weight. Energy consumed from soda was recorded as were food choices that were low in fat (<20% of calories from fat) or high in simple sugars (>30%). Food choices were expressed as percentage of daily energy intake. A subset of 85 subjects had measurement of follow-up weights and oral glucose tolerance (57 men, 28 women; mean follow-up time=2.5±2.1 years, range 6 months to 9.9 years). Energy consumed from soda was negatively related to age (r=−0.27, P=0.0001) and choosing low-fat foods (r=-0.35, P<0.0001), but positively associated with choosing solid foods high in simple sugars (r=0.45, P<0.0001) and overall average daily energy intake (r=0.46, P<0.0001). Energy intake from food alone did not differ between individuals who did and did not consume beverage calories (P=0.11). Total daily energy intake had no relationship with change in weight (P=0.29) or change in glucose regulation (P=0.38) over time. However, energy consumed from soda correlated with change in weight (r=0.21, P=0.04). This relationship was unchanged after adjusting for follow-up time and initial weight. Soda consumption is a marker for excess energy consumption and is associated with weight gain.

A Snapshot of Eating Behavior, Food Tolerance, and Dietary Intake after Laparoscopic Adjustable Gastric Banding

Background: This study aimed to describe eating behaviors, food tolerance, and dietary intake after laparoscopic adjustable gastric banding (LAGB); explore associations between these variables; and examine the relationship between diet-related factors and percentage weight loss and quality of life after surgery. Methods: A cross-sectional survey was mailed to subjects who had previously undergone LAGB in Newcastle, Australia. Results: Sixty-seven subjects responded (55 females; mean age 49±11.5 years; postoperative body mass index [BMI] 34.5±5.4 kg/m2). Reported average weight loss since surgery was 20.5±9.2% (26.6±13.0 kg). Restraint (including flexible and rigid control) and disinhibition were higher than community norms and hunger trended toward being lower. The majority of respondents rated their eating ability as good (n=27, 40.3%) or excellent (n=15, 22.4%). Median reported energy intake was 4,833 kJ (3,823–5,961) per day. Protein and fat intake as a percentage of daily energy intake was within acceptable distribution ranges, although saturated fat intake exceeded recommendations. Fiber and several micronutrients were below estimated average requirements. BMI at time of surgery and satisfaction with eating ability were significantly associated with reported weight loss after surgery (adjusted R2=0.32, p<0.001), and satisfaction with eating ability and rigid control were significantly associated with physical well-being (adjusted R2=0.19, p=0.001). Conclusions: This study highlights that potential remains to improve aspects of eating behavior, food tolerance, and diet quality in some individuals who have undergone LAGB, and endorses the need for further development of multifactorial interventions to help optimize a range of diet-related factors after LAGB.

Food, energy and macronutrient contribution of out-of-home foods in school-going adolescents in Cotonou, Benin

The objective of the present study was to document the food, energy and macronutrient contribution of out-of-home prepared foods in school-going adolescents in Cotonou (Benin) and compare the food, energy and macronutrient intakes of low and high out-of-home consumers. We used a cross-sectional study with 24 h dietary recalls on two non-consecutive school days to collect food intake data. Low and high consumers were defined respectively as subjects whose percentage of daily energy intake from out-of-home foods was in the first and the third terciles of the sample distribution. The setting was twelve secondary schools in Cotonou with 656 adolescents aged 13-19 years. Out-of-home prepared foods contributed more than 40 % of the daily energy, fat, protein, carbohydrate and fibre intakes and of the daily weight of food in the adolescents. They were highly present at breakfast and as afternoon snacks in high consumers, providing respectively 94 and 82 % of the energy intake of high consumers at breakfast and as afternoon snacks. Low consumers ate more fruit and vegetables and cereal grain products than high consumers whereas high consumers consumed more sweet energy-dense foods. Both categories had a diet poor in fruit and vegetables (hardly one-fourth of the recommended 400 g) and high in fat. We concluded that out-of-home foods are important in the diet of urban school adolescents in Benin. Therefore, they should be investigated in depth and taken into account in the development of interventions to promote healthy diet and lifestyles in adolescents.

Energy Intake at Breakfast and Weight Change: Prospective Study of 6,764 Middle-aged Men and Women

To investigate the association between percentage of total daily energy intake consumed at breakfast and weight change in middle-aged men and women, the authors analyzed data from a prospective population-based cohort study from Norfolk, United Kingdom. Participants were 6,764 men and women aged 40-75 years at baseline (1993-1997). Participants completed a 7-day food diary at baseline, and objective measurements of height and weight were carried out at baseline and follow-up (1998-2000). Mean baseline body mass index (weight (kg)/height (m)(2)) was lowest among persons in the highest quintile of percentage of daily energy consumed at breakfast (mean values were 26.0 in the highest quintile and 26.3 in the lowest quintile), despite higher daily total energy intake in this group. Although all participants gained weight, increased percentage of daily energy consumed at breakfast was associated with relatively lower weight gain (adjusted beta coefficient = -0.021, 95% confidence interval: -0.035, -0.007; p = 0.004). The association between percentage of daily energy intake consumed at breakfast and weight gain was independent of age, sex, smoking, total energy intake, macronutrient intake, social class, and physical activity. Redistribution of daily energy intake, so that more energy is consumed at breakfast and less energy is consumed later in the day, may help to reduce weight gain in middle-aged adults.

Fat and fatty acids intake of adults in eastern Croatia

The objective of this work was to determine dietary intake of total fat and fatty acids in adults in eastern Croatia. Thirty nine participants (25 women and 14 men) took part in a duplicate diet study. Total fat was extracted from the duplicated portions using a method by Bligh and Dyer, and fatty acids were determined using a GC analysis after methylation with boron trifluoride. Mean fat and fatty acids intakes for all subjects expressed as percentage of daily energy intake (% E) were: 33.4%, 9.9%, 11.8%, 9.0%, and 0.7% for total fat, saturated, monounsaturated, polyunsaturated, and trans fatty acids, respectively. The differences between sexes were not significant when expressed as % E. Also, a very low intake of linolenic acid (0.5% E), and a high linoleic acid/linolenic acid ratio (17.1), were noted. Because of the health implications of such an imbalance, further research on the prevalence of this in general population is warranted. Nevertheless, these results indicate a need for a more aggressive education of the public on health benefits of n-3 fatty acids and on their dietary sources.

BOYS FROM POPULATIONS WITH HIGH-CARBOHYDRATE INTAKE HAVE HIGHER FASTING TRIGLYCERIDE LEVELS THAN BOYS FROM POPULATIONS WITH HIGH-FAT INTAKE

Experimentally, high-carbohydrate diets have been shown to elevate triglycerides, but it has not been established whether this rise is permanent or transient. The authors approached this question by studying 719 boys from worldwide populations with marked differences in long-term carbohydrate intake. Fasting serum triglycerides, total cholesterol and high density lipoprotein (HDL) cholesterol concentrations were measured in boys aged 8 and 9 years from 12 countries--eight in Europe, three in Africa, and one in Asia. A standardized protocol was used for obtaining fasting blood and for the preparation, storage and transport of serum, and all measurements were made in one laboratory. Published values were used for the United States. Mean values for lipid levels per country were compared with the percentage of daily energy intake consumed as carbohydrate or fat, as determined by survey. Boys from populations with higher carbohydrate and lower fat intake had lower low density lipoprotein (LDL) cholesterol levels (univariate regression coefficient (+/- standard error, -0.028 +/- 0.009 mmol/liter for each percent of energy from carbohydrate; p less than 0.01, n = 13), but they also had higher fasting triglycerides (0.010 +/- 0.002 mmol/liter for each percent of energy from carbohydrate; p less than 0.01, n = 13) and lower HDL cholesterol levels (-0.022 +/- 0.003 mmol/liter for each percent of energy from carbohydrate; p less than 0.001, n = 13). These trends agree with results from epidemiologic studies within populations and from controlled dietary trials, and suggest that in normolipidemic healthy subjects, high-carbohydrate, low-fat diets cause higher triglyceride levels than diets that are higher in fats and oils.

Dietary protein requirements of physically active individuals.

The dietary protein requirement of physically active individuals has received considerable scrutiny in recent years. Because the current United States Recommended Daily Allowance (USRDA) for protein (0.8 g/kg/day) already contains a safety margin (0.35 g/kg/day) to assure adequate protein intake, no increment in the USRDA was thought necessary to meet the demands of physical activity. Recently, collective evidence from research techniques utilising nitrogen balance, labelled amino acid isotopes, urea production and 3-methylhistidine excretion indicates that exercise (endurance and weightlifting) can significantly alter protein metabolism and that the dietary protein needs of physically active individuals may exceed the current USRDA. During endurance exercise, protein synthesis is depressed and protein degradation increases. Thus, amino acids become available for oxidation in energy-yielding processes. Amino acid catabolism has been estimated to contribute between 5 and 15% of the energy required during endurance exercise. Definitive conclusions regarding the changes that occur in protein synthesis and protein degradation during weightlifting exercise must await further research. The net contribution of amino acids to the energy required during weightlifting exercise is unknown but, due to the anaerobic nature of the event, it is most likely less than during endurance exercise. However, following both endurance and weightlifting exercise, protein synthesis increases. Based on current research, it is not yet possible to make recommendations for the daily protein needs of exercising individuals. It does appear that physically active individuals require more dietary protein per kilogram of bodyweight than sedentary individuals. However, when protein intake is expressed as a percentage of daily energy intake, physically active and sedentary individuals have similar requirements (approximately 12 to 15% of total energy as protein). Therefore, to cover the protein requirements of both physically active individuals and sedentary individuals it is suggested that future protein allowances be based on a percentage of the daily energy requirements. Protein consumption in excess of the current USRDA may minimise changes in body nitrogen stores, particularly during the first few weeks of training. However, further research is needed before a definitive conclusion can be made regarding protein ingestion and athletic performance.