1.
The amount and types of fatty acids acutely affect insulin, glycemic and gastrointestinal peptide responses but not satiety in metabolic syndrome subjects.
Chang, CY, Kanthimathi, MS, Tan, AT, Nesaretnam, K, Teng, KT
European journal of nutrition. 2018;(1):179-190
Abstract
PURPOSE Limited clinical evidence is available on the effects of amount and types of dietary fats on postprandial insulinemic and gastrointestinal peptide responses in metabolic syndrome subjects. We hypothesized that meals enriched with designated: (1) amount of fats (50 vs 20 g), (2) fats with differing fatty acid composition (saturated, SFA; monounsaturated, MUFA or n-6 polyunsaturated fatty acids, PUFA) would affect insulinemic and gastrointestinal peptide releases in metabolic syndrome subjects. METHODS Using a randomized, crossover and double-blinded design, 15 men and 15 women with metabolic syndrome consumed high-fat meals enriched with SFA, MUFA or n-6 PUFA, or a low-fat/high-sucrose (SUCR) meal. C-peptide, insulin, glucose, gastrointestinal peptides and satiety were measured up to 6 h. RESULTS As expected, SUCR meal induced higher C-peptide (45 %), insulin (45 %) and glucose (49 %) responses compared with high-fat meals regardless of types of fatty acids (P < 0.001). Interestingly, incremental area under the curve (AUC0-120min) for glucagon-like peptide-1 was higher after SUCR meal compared with MUFA (27 %) and n-6 PUFA meals (23 %) (P = 0.01). AUC0-120min for glucose-dependent insulinotropic polypeptide was higher after SFA meal compared with MUFA (23 %) and n-6 PUFA meals (20 %) (P = 0.004). Significant meal x time interaction (P = 0.007) was observed for ghrelin, but not cholecystokinin and satiety. CONCLUSIONS The amount of fat regardless of the types of fatty acids affects insulin and glycemic responses. Both the amount and types of fatty acids acutely affect the gastrointestinal peptide release in metabolic syndrome subjects, but not satiety.
2.
Walnut consumption increases satiation but has no effect on insulin resistance or the metabolic profile over a 4-day period.
Brennan, AM, Sweeney, LL, Liu, X, Mantzoros, CS
Obesity (Silver Spring, Md.). 2010;(6):1176-82
Abstract
Obesity and diabetes have been associated with increased consumption of highly processed foods, and reduced consumption of whole grains and nuts. It has been proposed, mainly on the basis of observational studies, that nuts may provide superior satiation, may lead to reduced calorie consumption, and may decrease the risk of type 2 diabetes; but evidence from randomized, interventional studies is lacking. A total of 20 men and women with the metabolic syndrome participated in a randomized, double-blind, crossover study of walnut consumption. Subjects had two 4-day admissions to the clinical research center where they were fed an isocaloric diet. In addition, they consumed shakes for breakfast containing either walnuts or placebo (shakes were standardized for calories, carbohydrate, and fat content). Appetite, insulin resistance, and metabolic parameters were measured. We found an increased level of satiety (overall P value = 0.0079) and sense of fullness (P = 0.05) in prelunch questionnaires following the walnut breakfast as compared to the placebo breakfast, with the walnut effect achieving significance on day 3 and 4 (P = 0.02 and P = 0.03). We did not find any change in resting energy expenditure, hormones known to mediate satiety, or insulin resistance when comparing the walnut vs. placebo diet. Walnut consumption over 4 days increased satiety by day 3. Long-term studies are needed to confirm the physiologic role of walnuts, the duration of time needed for these effects to occur, and to elucidate the underlying mechanisms.