1.
Timed-daily ingestion of whey protein and exercise training reduces visceral adipose tissue mass and improves insulin resistance: the PRISE study.
Arciero, PJ, Baur, D, Connelly, S, Ormsbee, MJ
Journal of applied physiology (Bethesda, Md. : 1985). 2014;117(1):1-10
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High-protein diets may promote weight loss and improved body composition via a number of mechanisms such as increasing satiety and promoting muscle synthesis. The aim of this study was to examine the effects of timed ingestion of whey protein on body weight, fat distribution, insulin resistance and hunger. A secondary aim was to assess the effect of different exercise regimes on the same outcomes. Participants were sedentary and overweight or obese, but otherwise healthy, adults. For 16 weeks, all participants consumed three 20g servings of whey protein per day; within 1 hour of waking, mid-afternoon or within 30 minutes of exercise, and within 2 hours of going to bed (P). Some participants were also assigned to an exercise regime consisting of either resistance and sprint training (RT) or a mixed regime of resistance training, interval training, stretching and endurance (RISE). All participants continued to consume their usual diets. All three groups saw improvements in markers of their body composition and cardiometabolic health, regardless of whether they exercised or not. However, the combined effects of whey protein and exercise resulted in additional improvements in visceral fat, adipokines and insulin sensitivity. Whey protein plus the mixed exercise regime (RISE) was associated with the greatest improvements and the authors concluded that this is an effective lifestyle intervention for overweight and obese adults.
Abstract
The present study examined the effects of timed ingestion of supplemental protein (20-g servings of whey protein, 3×/day), added to the habitual diet of free-living overweight/obese adults and subsequently randomized to either whey protein only (P; n = 24), whey protein and resistance exercise (P + RT; n = 27), or a whey protein and multimode exercise training program [protein and resistance exercise, intervals, stretching/yoga/Pilates, endurance exercise (PRISE); n = 28]. Total and regional body composition and visceral adipose tissue (VAT) mass (dual-energy X-ray absorptiometry), insulin sensitivity [homeostasis model assessment-estimated insulin resistance (HOMA-IR)], plasma lipids and adipokines, and feelings of hunger and satiety (visual analog scales) were measured before and after the 16-wk intervention. All groups lost body weight, fat mass (FM), and abdominal fat; however, PRISE lost significantly (P < 0.01) more body weight (3.3 ± 0.7 vs. 1.1 ± 0.7 kg, P + RT) and FM (2.8 ± 0.7 vs. 0.9 ± 0.5 kg, P + RT) and gained (P < 0.05) a greater percentage of lean body mass (2 ± 0.5 vs. 0.9 ± 0.3 and 0.6 ± 0.4%, P + RT and P, respectively). Only P + RT (0.1 ± 0.04 kg) and PRISE (0.21 ± 0.07 kg) lost VAT mass (P < 0.05). Fasting glucose decreased only in P + RT (5.1 ± 2.5 mg/dl) and PRISE (15.3 ± 2.1 mg/dl), with the greatest decline occurring in PRISE (P < 0.05). Similarly, HOMA-IR improved (0.6 ± 0.3, 0.6 ± 0.4 units), and leptin decreased (4.7 ± 2.2, 4.7 ± 3.1 ng/dl), and adiponectin increased (3.8 ± 1.1, 2.4 ± 1.1 μg/ml) only in P + RT and PRISE, respectively, with no change in P. In conclusion, we find evidence to support exercise training and timed ingestion of whey protein added to the habitual diet of free-living overweight/obese adults, independent of caloric restriction on total and regional body fat distribution, insulin resistance, and adipokines.
2.
Insulin-like growth factor I response during nutritional rehabilitation of persistent diarrhoea.
Bhutta, ZA, Bang, P, Karlsson, E, Hagenäs, L, Nizami, SQ, Söder, O
Archives of disease in childhood. 1999;80(5):438-42
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Persistent diarrhoea in childhood causes severe malnutrition, and morbidity in 15%+ cases. Treatment includes nutritional rehabilitation for weight gain and diarrheal recovery. This study evaluates nutritional recovery (defined as weight gain (> 5 g/kg/day) with a resolution of diarrhea by day 7 of treatment), intestinal permeability and insulin-like growth factor I (IGF-I) response in malnourished children with faltering growth (aged 6-36 months) with persistent diarrhoea ((>/= 14 days) and their relation to concomitant systemic infection(s) (as indicated by serum C reactive protein (CRP)). For a minimum of 7 days, 63 children were fed a previously validated dietary regimen (data not available) of rice–lentil (khitchri) and yogurt aimed at providing at least 100 kcal/kg/day by day 3, with ad libitum feeds thereafter. Children were nursed on a research ward throughout. 49 children were treatment successes. They had a significant increase in serum IGF-I and IGF-I% correlated with weight gain. 14 children did not meet the criteria for nutritional recovery. They had higher serum CRP concentrations and sepsis at admission. They had lower mean (SD) weight gain in spite of overall mean energy intake being comparable with treatment successes. This may indicate malabsoption. Admission CRP concentration and IGF-I were negatively correlated. CRP concentrations at admission and corresponding individual IGF-I values over the 7 days treatment were significantly correlated. Significantly raised CRP concentrations in children with a correspondingly low IGF-I response may indicate a continued inflammatory or infected state in these children. Small but opposing trends of urinary excretion of the oral lactulose dose were seen in both groups over the seven days of treatment, indicating worsening enteropathy (mucosal injury) among treatment failures. None of the permeability parameters correlated with IGF-I at baseline or recovery. The study confirms that a traditional rice–lentil (khitchri) and yogurt diet can be used successfully for enteral nutritional rehabilitation in malnourished children with persistent diarrhoea and leads to adequate weight gain; Serum IGF-I levels correlates closely with weight gain and reduction in stool output; recovery is delayed with sepsis and raised blood CRP concentrations at admission; IGF-I is depressed at admission in children with persistent diarrhoea. The data provide evidence that serum IGF-I response in recovering malnourished children with persistent diarrhoea may provide a sensitive measure of nutritional and diarrhoeal recovery. Further studies are needed to evaluate factors regulating the IGF-I response in such children, especially the effect of intercurrent infections. Arbitrary definition of treatment failure is a study limitation.
Abstract
OBJECTIVE Evaluation of nutritional recovery, intestinal permeability, and insulin-like growth factor I (IGF-I) response in malnourished children with persistent diarrhoea and their relation to concomitant systemic infection(s). STUDY DESIGN Open study of severely malnourished children (aged 6-36 months) with persistent diarrhoea (≥ 14 days) admitted for nutritional rehabilitation with a standardised rice-lentil and yogurt diet. Successful recovery was defined prospectively as overall weight gain (> 5 g/kg/day) with a reduction in stool output by day 7 of treatment. Data on coexisting infections and serum C reactive protein (CRP) were collected at admission. RESULTS Of 63 children, 48 (group A) recovered within seven days of dietary treatment. These children had a significant increase in serum IGF-I (DeltaIGF-I%) and, in contrast to serum prealbumin and retinol binding protein, DeltaIGF-I% correlated with weight gain (r = 0.41). There was no correlation between the IGF-I response and intestinal permeability as assessed by urinary lactulose/rhamnose excretion. Treatment failures (group B) included more children with clinical (relative risk, 4.8; 95% confidence interval, 1.2 to 19.7) and culture proven sepsis at admission and higher concentrations of serum CRP (median (range), 36 (0-182) v 10 (0-240) mg/l) at admission. There was a negative correlation between admission CRP concentration and DeltaIGF-I% (r = -0.45). CONCLUSIONS In comparison with serum albumin, prealbumin, and retinol binding protein, serum IGF-I increment is a better marker of nutritional recovery in malnourished children with persistent diarrhoea. The possible association of systemic infections, serum IGF-I response, and mucosal recovery needs evaluation in future studies.