The influence of nighttime feeding of carbohydrate or protein combined with exercise training on appetite and cardiometabolic risk in young obese women.

Single macronutrient intake prior to sleep reduces appetite but may negatively impact insulin sensitivity in sedentary obese women. The present study examined the additive impact of nighttime feeding of whey (WH), casein (CAS), or carbohydrate (CHO) combined with exercise training on appetite, cardiometabolic health, and strength in obese women. Thirty-seven sedentary obese women (WH, n = 13, body mass index (BMI) 34.4 ± 1.3 kg/m(2); CAS, n = 14, BMI 36.5 ± 1.8 kg/m(2); CHO, n = 10, BMI 33.1 ± 1.7 kg/m(2)) consumed WH, CAS, or CHO (140-150 kcal/serving), every night of the week, within 30 min of sleep, for 4 weeks. Supervised exercise training (2 days of resistance training and 1 day of high-intensity interval training) was completed 3 days per week. Pre- and post-testing measurements included appetite ratings, mood state, resting metabolic rate, fasting lipids, glucose, and hormonal responses (insulin, leptin, adiponectin, hs-CRP, IGF-1, and cortisol), body composition, and strength. Nighttime intake of CAS significantly (p < 0.05) increased morning satiety (pretraining, 25 ± 5; post-training 41 ± 6) more than WH (pretraining, 34 ± 5; post-training, 35 ± 6) or CHO (pre 40 ± 8, post 43 ± 7). Exercise training increased lean mass and strength, decreased body fat, and improved mood state in all groups. No other differences were noted. Nighttime feeding of CAS combined with exercise training increased morning satiety more than WH or CHO. Nighttime feeding for 4 weeks did not impact insulin sensitivity (assessed via homeostatic model assessment of insulin resistance) when combined with exercise training in obese women. ClinicalTrial.gov: NCT01830946.

Influence of night-time protein and carbohydrate intake on appetite and cardiometabolic risk in sedentary overweight and obese women.

The present study investigated whether whey (WH) protein, casein (CAS) protein or a carbohydrate placebo (PLA) consumed 30 min before sleep could acutely alter appetite or cardiometabolic risk the following morning. A total of forty-four sedentary overweight and obese women (BMI: 25·7-54·6 kg/m2) completed this stratified, randomised, double-blind, placebo-controlled study (WH: n 16, age 27·4 (sd 5·0) years; CAS: n 15, age 30·3 (sd 8·1) years; PLA: n 13, age 28·5 (sd 7·2) years). The participants came to the laboratory at baseline (visit 1) and again in the morning after night-time ingestion of either protein or PLA (visit 2). Visit 2 was conducted at least 48 h after visit 1. During visits 1 and 2, the following parameters were measured: appetite (hunger, satiety and desire to eat); resting metabolism; blood lipid and glucose levels; the levels of insulin, leptin, C-reactive protein, insulin-like growth factor-1, cortisol and adiponectin. Data were analysed using repeated-measures ANOVA. No group × time interactions were observed for the measured variables; however, a main effect of time was observed for increased satiety (P= 0·03), reduced desire to eat (P= 0·006), and increased insulin levels (P= 0·004) and homeostatic model assessment of insulin resistance values (P= 0·01) after the consumption of either protein or PLA. The results of the present study reveal that night-time consumption of protein or carbohydrate by sedentary overweight and obese women improves their appetite measures but negatively affects insulin levels. Long-term studies are needed to evaluate the effects of chronic consumption of low-energy snacks at night on body composition and cardiometabolic risk.

Effects of milk proteins and combined exercise training on aortic hemodynamics and arterial stiffness in young obese women with high blood pressure.

BACKGROUND: Obesity and reduced muscle strength are associated with increased blood pressure (BP). We examined the impact of milk proteins and combined exercise training (CET) on BP, arterial function, and muscle strength (one-repetition maximum (1-RM)). METHODS: Thirty-three obese sedentary women (age = 30 ± 1 years; body mass index = 35.2 ± 0.9 kg/m(2); systolic BP (SBP) = 129 ± 2 mm Hg) were randomized to control carbohydrate (n = 11), whey (n = 11), and casein (n = 11) supplementation for 4 weeks. All participants performed moderate-intensity CET 3 days/week. Brachial and aortic SBP, augmentation index adjusted for 75 beats/minute (AIx@75), arterial stiffness (brachial-ankle pulse wave velocity (baPWV)), and 1-RM were measured before and after the interventions. RESULTS: There were significant (P < 0.05) time-by-group interactions for brachial SBP (bSBP), aortic SBP (aSBP), AIx@75, and baPWV. Whey and casein supplementation significantly (P < 0.05) decreased bSBP (approximately 5mm Hg for both), aSBP (approximately 7 mm Hg and approximately 6mm Hg, respectively), AIx@75 (approximately 9.2% and approximately 8.1%, respectively) and baPWV (approximately 57 cm/s and approximately 53 cm/s, respectively) compared with no changes in the control group. Upper- (approximately 22.2%) and lower-body 1-RM (approximately 44.0%) increased similarly in all groups. Changes in arterial function and 1-RM were not correlated. CONCLUSIONS: Milk protein supplementation with CET reduced SBP, wave reflection, and arterial stiffness in young obese women with prehypertension and hypertension. Because CET did not affect arterial function, milk proteins may have an antihypertensive effect by improving arterial function, as shown by reduced AIx@75 and baPWV. Muscle strength improvements after CET did not affect BP and arterial function. CLINICAL TRIAL REGISTRATION: ClinicalTrial.gov Registration NCT01830946.