Moderate Energy-restricted Diet Research Articles

Case Study: The Effect of Nutritional Intervention on Body Composition and Physical Performance of a Female Squash Player.

The body composition of a squash player may affect athletic performance as carrying excessive body fat may increase injury risk and impair agility and speed. This case study outlines the effect of a nutritional intervention on body composition, vitaminD status, and physical performance of a female squash player. A structured, 6-week, moderate energy-restricted diet (70-78% of estimated energy requirement of 2,300kcal) was implemented with weekly support. A daily supplement of vitaminD, omega-3 fatty acids, and a multivitamin and whey protein was used. Full blood count, vitaminD status, body composition, and physical performance assessments were carried out at baseline and Week 6 of intervention. Body composition changes were measured using the BOD POD™ and skinfold calipers. Body fat was 23% at baseline and 22% at Week 6. Mean sum of eight skinfolds was 127.4 ± 2.2mm at baseline and 107.3 ± 0.4mm at Week 6. Lean body mass-to-fat mass ratio improved from 3.4 at baseline to 3.7 at Week 6. The greatest increments compared with baseline in serum markers were 25-hydroxyvitamin D3 (68%), ferritin (31%), eosinophils (20%), and triglycerides (16%). All physical performance measures improved, with reactive strength index (4.8%), and on-court repeated speed (6.0%) showing the greatest improvements from baseline. This intervention demonstrates that structured energy restriction alongside appropriately structured strength and conditioning training is an effective way to gradually reduce the body fat and improve the body composition of a female athlete.

Effects of dairy foods in a moderate energy restricted diet on inflammatory markers and plasma zinc in overweight and obese adults

Pro-inflammatory cytokines and acute phase proteins are often elevated in obesity, while plasma Zn is often lower. Healthy overweight and obese (BMI = 28–37) men (n=18) and women (n=53) were randomly assigned to an adequate dairy (AD: 3–4 servings/d) or low dairy (LD: ≤ 1 serving/d) 12 wk controlled diet of 500 kcal/d reduction from baseline energy needs. Body fat (BF), lean body mass (LBM), and fasting levels of circulating insulin, leptin, adiponectin, IL1-β, IL-6, IL-8, TNF-α, PAI-1, hsCRP and Zn were measured. Mean weight loss was 6.1 kg. Significant decreases (p<0.05) from baseline to 12 wk included body weight (6.8%), BF (14.2%), LBM (1.6%), insulin (12.2%), leptin (24.9%), PAI-1 (12.7%) & hsCRP (22.8%). All decreases correlated with BF loss, but no differences were observed between AD & LD. Plasma Zn increased (p<0.05) in the AD group (9.5%), which was not explained by dietary Zn intake. IL1- β and IL-6 changes were correlated with the change in LBM; if LBM was conserved IL1- β and IL-6 levels decreased (p<0.05). In summary, a modest weight loss of 6 kg over 12 wks improved markers of inflammation, and adding dairy foods to the weight loss diet increased plasma Zn. Funding: National Dairy Council; USDA, ARS, WHNRC; Dairy Council of CA; CTSC, Clinical Research Center at the University of CA (1M01RR19975-01), and National Center for Medical Research (UL1 RR024146)

Dairy Foods in a Moderate Energy Restricted Diet Do Not Enhance Central Fat, Weight, and Intra-Abdominal Adipose Tissue Losses nor Reduce Adipocyte Size or Inflammatory Markers in Overweight and Obese Adults: A Controlled Feeding Study

Background. Research on dairy foods to enhance weight and fat loss when incorporated into a modest weight loss diet has had mixed results. Objective. A 15-week controlled feeding study to determine if dairy foods enhance central fat and weight loss when incorporated in a modest energy restricted diet of overweight and obese adults. Design. A 3-week run-in to establish energy needs; a 12-week 500 kcal/d energy reduction with 71 low-dairy-consuming overweight and obese adults randomly assigned to diets: ≤1 serving dairy/d (low dairy, LD) or ≤4 servings dairy/d (adequate dairy, AD). All foods were weighed and provided by the metabolic kitchen. Weight, fat, intra-abdominal adipose tissue (IAAT), subcutaneous adipose tissue (SAT) macrophage number, SAT inflammatory gene expression, and circulating cytokines were measured. Results. No diet differences were observed in weight, fat, or IAAT loss; nor SAT mRNA expression of inflammation, circulating cytokines, fasting lipids, glucose, or insulin. There was a significant increase (P = 0.02) in serum 25-hydroxyvitamin D in the AD group. Conclusion. Whether increased dairy intake during weight loss results in greater weight and fat loss for individuals with metabolic syndrome deserves investigation. Assessment of appetite, hunger, and satiety with followup on weight regain should be considered.

Vitamin D Status in Overweight and Obese Individuals During A Controlled Calorie Restricted Intervention

Vitamin D deficiency is common in obese subjects and status may be improved with dietary interventions. We examined serum 25(OH)D in overweight and obese individuals enrolled in a controlled calorie restricted intervention. Serum samples from overweight and obese (BMI = 28–37) subjects (F=53, M=18), participating in a study examining dairy's role in weight and fat loss, were taken pre‐ and post‐intervention. Participants were randomly assigned to either a high dairy (HD: 3–4 servings; average 333IU D) or low dairy (LD: ≤ 1 serving/d, average 151 IU D) for 12 wks. Energy balance was achieved in wks 1–3 followed by 12wk of 500 kcal/d reduction. All foods were supplied by the metabolic food lab. Outcome variables were body weight (WT), body fat (BF) determined by DXA and serum 25(OH)D measured by RIA. When controlling for total body fat mass, ANOVA showed a significant treatment effect with a greater increase in the %change of serum 25(OH)D in the high dairy group (27.27 ± 37.47 nmol; p = 0.05) compared to the low dairy group(13.16 ± 32.7 nmol; p = .09). The inclusion of 3–4 servings of vitamin D fortified dairy rich foods in a moderate energy restricted diet may contribute to an improved vitamin D status in overweight and obese individuals.Funding: National Dairy Council; USDA, ARS, WHNRC; DairyCouncil of California; CTSC, CCRC University of California (1M01RR19975‐01), and National Center for Medical Research (UL1 RR024146).

Does Inclusion of Dairy Foods in a Moderate Energy Restricted Diet Enhance Central Fat and Weight Loss in Overweight and Obese Adults?

Research suggests high Ca or dairy intake contributes to greater weight and fat loss; this remains controversial. We examined the role of dairy food in a moderate energy restricted diet to enhance central fat and weight (WT) loss in overweight and obese adults, whose dairy consumption was ≤1 serving/d &amp; ≤ 600 mg of dietary Ca/d. Overweight and obese (BMI = 27.4–37.5 kg/m2) men (n=20) and women (n=51) were randomly assigned to a high dairy (HD: 3–4 servings/d = 1369mg Ca/d) or low dairy (LD: ≤ 1 serving/d = 481mg Ca/d) 12 wk controlled diet. Energy balance was achieved in wks 1–3 followed by 12wk of 500 kcal/d reduction. All food was supplied by the metabolic kitchen. WT, body fat (BF) by DXA, and intra‐abdominal adipose tissue (IAAT) by CT‐scan were measured pre‐ and post‐intervention. GLM analysis adjusted for initial WT, BF and IAAT showed no significant difference in percent change of WT (p = 0.94), BF (p = 0.68) or IAAT (p = 0.41) by treatment. Treatment Δ Weight, kg Δ Body Fat, kg Δ Intra‐abdominal Adipose Tissue, cc HD −6.20 ± 2.9 −5.19 ± 2.7 −8.0 ± 6.9 LD −6.04 ± 3.2 −5.36 ± 3.0 −10.26 ± 9.73 An energy restricted diet with 3–4 servings of dairy does not enhance central fat or weight loss over energy restriction alone. Funding: National Dairy Council; USDA, ARS, WHNRC; Dairy Council of California; CTSC, Clinical Research Center at the University of California (1M01RR19975‐01), and National Center for Medical Research (UL1 RR024146)

The Role of Dairy Foods and Dietary Calcium in Weight Management

Overweight and obesity are the foremost public health problems in the U.S., other industrialized countries, and is rapidly increasing in developing countries. Obesity is a multifaceted disease which requires multiple approaches to successfully combat its increase. Nutritional factors play a key role and include modification of energy balance, intake and expenditure, as well as other factors. Emerging scientific evidence over the past decade suggests that dairy foods may be beneficial when included in a moderate energy restricted diet and possibly for weight maintenance as well. This paper provides a review of some of the scientific evidence that has examined the effect of dairy foods and dietary calcium on weight management. Topic areas presented are observational or retrospective studies with adults as well as children and adolescents; randomized clinical trials on body weight and composition, energy expenditure, substrate oxidation and fecal fat loss; research from animal and in vitro studies provide possible mechanisms of action.

Effect of caloric restriction with and without exercise training on oxidative stress and endothelial function in obese subjects with type 2 diabetes

Effects of dietary weight loss on endothelial function, particularly when combined with exercise training, is largely unknown in type 2 diabetes. We sought to determine whether aerobic exercise training provided any additional improvements in endothelial function, oxidative stress or other established markers of cardiovascular risk when combined with an energy-restricted diet in patients with type 2 diabetes. In a parallel study design, 29 sedentary, overweight and obese patients with type 2 diabetes (age 52.4 +/- 1.4 years and BMI 34.2 +/- 0.9 kg/m(2)) were randomized to a 12-week moderate energy-restricted diet (~5000 kJ/day and approximately 30% energy deficit) with or without aerobic exercise training [diet only (D), n = 16 and diet plus exercise (DE), n = 13]. Body weight, cardiovascular risk markers, malondialdehyde (MDA, oxidative stress marker), 24-h urinary nitrate/nitrite and flow-mediated dilatation (FMD) of the brachial artery were measured pre- and postintervention. Both interventions reduced body weight (D 8.9%, DE 8.5%, time effect p < 0.001). Significant reductions in body fat, waist circumference, blood pressure, glycated haemoglobin, glucose, insulin resistance, lipids and MDA and increases in urinary nitrite/nitrate were observed in both groups (time effect p < or = 0.05); however, these changes were not different between treatments. At baseline, FMD was similar in both groups (D 2.5 +/- 0.9%, DE 4.2 +/- 1.2%; p = 0.25) and did not change after the interventions (p = 0.59). These results suggest that lifestyle interventions incorporating diet with or without exercise improve glycaemic control, reduce oxidative stress and improve other cardiovascular risk factors but do not improve FMD in obese subjects with type 2 diabetes.

Moderate energy restriction increases bone resorption in obese postmenopausal women

Weight reduction reduces bone mineral density (BMD) and increases the risk of osteoporosis. We investigated whether bone is mobilized in postmenopausal women during energy restriction and whether hormones regulate bone turnover and mass. Twenty-seven obese postmenopausal women with a mean (+/-SD) age of 55.9 +/- 7.9 y and body mass index (in kg/m(2)) of 33.0 +/- 3.8 completed the 6-mo study. Fourteen women followed a moderate energy-restricted diet (WL group) and 13 control subjects maintained their body weight (WM group). Body weight, bone turnover markers, serum parathyroid hormone (PTH), and dietary intake were measured throughout the study. Total-body BMD, sex hormone binding globulin, leptin, and estrone were measured at baseline and at week 25. In the WL group, body weight decreased by 10.2 +/- 5.5% (P < 0.001), body fat mass decreased by 18.7 +/- 11.3% (P < 0.001), and total-body BMD decreased by 1.2 +/- 1.2%; these changes were significantly different from those in the WM group (P < 0.05). Serial measurements showed chronically elevated rates of bone resorption and formation during energy restriction that were greater than in the WM group (P < 0.05). Serum sex hormone binding globulin increased and leptin decreased with weight loss (P < 0.05). Serum PTH tended to increase in the WL group but not in the WM group (P < 0.06). The reduction in fat mass with weight loss was directly associated with a decrease in serum estrone (P < 0.01, R(2) = 0.50). Moderate energy restriction increases bone turnover in obese postmenopausal women and may be regulated in part by alterations in serum PTH and estrone.