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The Weight Optimization Revamping Lifestyle using the Dietary Guidelines (WORLD) Study: Sustained Weight Loss Over 12 Months.
Psota, TL, Tindall, AM, Lohse, B, Miller, PE, Petersen, KS, Kris-Etherton, PM
Obesity (Silver Spring, Md.). 2020;28(7):1235-1244
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Effective long-term weight loss strategies to reduce the risk of death and diseases associated with being obese or overweight are required, as restrictive programmes are difficult to sustain, and weight loss may be heavily influenced by behavioural factors. This randomised control trial of 101 premenopausal women with obesity or overweight aimed to compare a lower-fat and moderate-fat diets, both with nutrition education for 12 months. The results showed that both treatment groups lost weight. Both groups consumed the same amount of fat but increased their diet quality. Diet quality and greater attendance at nutritional education sessions were associated with greater weight loss. Cholesterol was significantly lower in both groups, but blood pressure remained unchanged. Interestingly there were a large number of women who did not complete the trial. It was concluded that irrespective of the amount of fat consumed, nutrition education can help to achieve sustained weight loss, improve diet quality and decrease heart disease risk for at least 12 months. This study could be used by healthcare professionals to understand that recommending fat-based targets for weight loss may be ineffective and the importance of emotional and behavioural support for individuals on a weight loss regime to improve their risk for heart disease.
Abstract
OBJECTIVE This study aimed to compare two energy-restricted, nutrient-dense diets at the upper or lower ends of the dietary fat recommendation range (lower fat [20% energy from fat] versus moderate fat [35%]) on weight loss using behavioral theory-based nutrition education. METHODS A total of 101 premenopausal women with overweight or obesity were randomized to an energy-restricted lower-fat or moderate-fat diet for 1 year. Interventions included 28 behavioral theory-based nutrition education sessions plus weekly exercise sessions. RESULTS Both treatment groups experienced weight loss (-5.0 kg for lower fat and -4.3 kg for moderate fat; P < 0.0001), but there was no difference in weight loss or fat intake between groups. Total and low-density lipoprotein cholesterol decreased (-3. 4 mg/dL and -3.8 mg/dL; P < 0.05), and high-density lipoprotein cholesterol increased (1.9 mg/dL; P < 0.05) in both groups at 12 months. Diet quality, assessed by the Healthy Eating Index, increased significantly at 4 months versus baseline (70.8 [0.9] vs. 77.8 [1.0]) and was maintained through 12 months. Higher Healthy Eating Index scores were associated with greater weight loss at 4 months (r = -0.2; P < 0.05). CONCLUSIONS In the context of a well-resourced, free-living weight-loss intervention, total fat intake did not change; however, theory-based nutrition education underpinned by food-based recommendations resulted in caloric deficits, improvements in diet quality, and weight loss that was sustained for 1 year.
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Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males.
Moro, T, Tinsley, G, Bianco, A, Marcolin, G, Pacelli, QF, Battaglia, G, Palma, A, Gentil, P, Neri, M, Paoli, A
Journal of translational medicine. 2016;14(1):290
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Time-restricted feeding (TRF) allows subjects to consume ad libitum energy intake within a defined window of time, which means a fasting window of 12–21 h per day is employed. The aim of the present study was to investigate the effects of an isoenergetic TRF protocol on body composition, athletic performance, and metabolic factors during resistance training in healthy resistance trained males. The study enrolled thirty-four resistance-trained males. The participants were randomly assigned to a TRF group (n = 17) or standard diet group (n = 17). Training was standardized for both groups. Results indicate that after 8 weeks, a significant decrease in fat mass was observed in the TRF group, while fat-free mass was maintained in both groups. The same trend was observed for arm and thigh muscle cross-sectional area. Leg press maximal strength increased significantly, but no difference was present between treatments. Authors conclude that TRF can maintain muscle mass, reducing body fat, and reducing inflammation markers and anabolic hormones. This kind of regimen could be adopted by athletes during maintenance phases of training in which the goal is to maintain muscle mass while reducing fat mass.
Abstract
BACKGROUND Intermittent fasting (IF) is an increasingly popular dietary approach used for weight loss and overall health. While there is an increasing body of evidence demonstrating beneficial effects of IF on blood lipids and other health outcomes in the overweight and obese, limited data are available about the effect of IF in athletes. Thus, the present study sought to investigate the effects of a modified IF protocol (i.e. time-restricted feeding) during resistance training in healthy resistance-trained males. METHODS Thirty-four resistance-trained males were randomly assigned to time-restricted feeding (TRF) or normal diet group (ND). TRF subjects consumed 100 % of their energy needs in an 8-h period of time each day, with their caloric intake divided into three meals consumed at 1 p.m., 4 p.m., and 8 p.m. The remaining 16 h per 24-h period made up the fasting period. Subjects in the ND group consumed 100 % of their energy needs divided into three meals consumed at 8 a.m., 1 p.m., and 8 p.m. Groups were matched for kilocalories consumed and macronutrient distribution (TRF 2826 ± 412.3 kcal/day, carbohydrates 53.2 ± 1.4 %, fat 24.7 ± 3.1 %, protein 22.1 ± 2.6 %, ND 3007 ± 444.7 kcal/day, carbohydrates 54.7 ± 2.2 %, fat 23.9 ± 3.5 %, protein 21.4 ± 1.8). Subjects were tested before and after 8 weeks of the assigned diet and standardized resistance training program. Fat mass and fat-free mass were assessed by dual-energy x-ray absorptiometry and muscle area of the thigh and arm were measured using an anthropometric system. Total and free testosterone, insulin-like growth factor 1, blood glucose, insulin, adiponectin, leptin, triiodothyronine, thyroid stimulating hormone, interleukin-6, interleukin-1β, tumor necrosis factor α, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured. Bench press and leg press maximal strength, resting energy expenditure, and respiratory ratio were also tested. RESULTS After 8 weeks, the 2 Way ANOVA (Time * Diet interaction) showed a decrease in fat mass in TRF compared to ND (p = 0.0448), while fat-free mass, muscle area of the arm and thigh, and maximal strength were maintained in both groups. Testosterone and insulin-like growth factor 1 decreased significantly in TRF, with no changes in ND (p = 0.0476; p = 0.0397). Adiponectin increased (p = 0.0000) in TRF while total leptin decreased (p = 0.0001), although not when adjusted for fat mass. Triiodothyronine decreased in TRF, but no significant changes were detected in thyroid-stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, or triglycerides. Resting energy expenditure was unchanged, but a significant decrease in respiratory ratio was observed in the TRF group. CONCLUSIONS Our results suggest that an intermittent fasting program in which all calories are consumed in an 8-h window each day, in conjunction with resistance training, could improve some health-related biomarkers, decrease fat mass, and maintain muscle mass in resistance-trained males.