Return of hunger following a relatively high carbohydrate breakfast is associated with earlier recorded glucose peak and nadir.

The aim of this study is to test the hypothesis that a breakfast meal with high carbohydrate/low fat results in an earlier increase in postprandial glucose and insulin, a greater decrease below baseline in postprandial glucose, and an earlier return of appetite, compared with a low carbohydrate/high fat meal. Overweight but otherwise healthy adults (n = 64) were maintained on one of two eucaloric diets: high carbohydrate/low fat (HC/LF; 55:27:18% kcals from carbohydrate:fat:protein) versus low carbohydrate/high fat (LC/HF; 43:39:18% kcals from carbohydrate:fat:protein). After 4 weeks of acclimation to the diets, participants underwent a meal test during which circulating glucose and insulin and self-reported hunger and fullness, were measured before and after consumption of breakfast from their assigned diets. The LC/HF meal resulted in a later time at the highest and lowest recorded glucose, higher glucose concentrations at 3 and 4 hours post meal, and lower insulin incremental area under the curve. Participants consuming the LC/HF meal reported lower appetite 3 and 4 hours following the meal, a response that was associated with the timing of the highest and lowest recorded glucose. Modest increases in meal carbohydrate content at the expense of fat content may facilitate weight gain over the long-term by contributing to an earlier rise and fall of postprandial glucose concentrations and an earlier return of appetite.

High-milk supplementation with healthy diet counseling does not affect weight loss but ameliorates insulin action compared with low-milk supplementation in overweight children.

Milk consumption has decreased in children over the past years. This may play a role in the prevalence of pediatric obesity, because clinical studies have found a beneficial effect of milk consumption for weight management. The objectives of this study were to test whether high-milk consumption leads to greater weight loss and improvements in metabolic risk factors than low milk consumption during a 16-wk healthy eating diet. Overweight children aged 8-10 y were randomized to either high (4 x 236 mL/d) or low (1 x 236 mL/d) milk consumption. Children were provided dietary counseling on healthy eating at baseline and at wk 1, 2, 4, 6, 8, and 12. Serum glucose, insulin, and lipids were measured in fasting children at baseline and wk 8 and 16. An oral glucose tolerance test and body composition assessment by magnetic resonance imaging were conducted at baseline and endpoint. Body weight changes during the 16-wk study not differ between the high-milk (1.3 +/- 0.3 kg) and low-milk (1.1 +/- 0.3 kg) groups. There was no beverage x week interaction on any of the body composition and metabolic variables studied (blood pressure, serum lipids, glucose, and insulin). There was a beverage x week interaction (P = 0.044) on insulin area under the curve showing a trend toward reduced insulin output with a glucose challenge after high-milk consumption (P = 0.062). These data suggest that in overweight children, high-milk consumption in conjunction with a healthy diet does not lead to greater weight loss but may ameliorate insulin action compared with low-milk consumption.

Medium chain triglyceride oil consumption as part of a weight loss diet does not lead to an adverse metabolic profile when compared to olive oil.

OBJECTIVE: Medium chain triglyceride (MCT) consumption may have a beneficial impact on weight management, however, some studies point to a negative impact of MCT oil consumption on cardiovascular disease risk. This study examined the effects of MCT oil consumption, as part of a weight loss diet, on metabolic risk profile compared to olive oil. DESIGN: Thirty-one men and women, age 19-50 y and body mass index 27-33 kg/m(2), completed this randomized, controlled, 16-week weight loss program. Oils were consumed at a level of approximately 12% of the subjects' prescribed energy intakes in the form of muffins and liquid oil. RESULTS: After controlling for body weight, there was a significant effect of time on fasting serum glucose (P = 0.0177) and total cholesterol (P = 0.0386) concentrations, and on diastolic blood pressure (P = 0.0413), with reductions in these variables occurring over time; there was no time-by-diet interaction for any of the parameters studied. Two of the 3 subjects in the MCT oil group with evidence of the metabolic syndrome at baseline did not have metabolic syndrome at endpoint. In the olive oil group, 6 subjects had the metabolic syndrome at baseline; 2 subjects no longer had metabolic syndrome at endpoint, 1 person developed metabolic syndrome, and 4 subjects did not have any change in their metabolic syndrome status. CONCLUSIONS: Our results suggest that MCT oil can be incorporated into a weight loss program without fear of adversely affecting metabolic risk factors. Distinction should be made regarding chain length when it comes to discussing the effects of saturated fats on metabolic risk factors.

Associations of free fatty acids with insulin secretion and action among African-American and European-American girls and women.

Ethnic differences in insulin secretion and action between African Americans (AAs) and European Americans (EAs) may influence mobilization of free fatty acids (FFAs). We tested the hypotheses that FFA concentrations would be associated with measures of insulin secretion and action before and during a glucose challenge test. Subjects were 48 prepubertal girls, 60 premenopausal women, and 46 postmenopausal women. Fasting insulin (insulin(0)), the acute insulin response to glucose (AIR(g)), the insulin sensitivity index (S(I)), basal and nadir FFA (FFA(0), FFA(nadir)), and nadir time (TIME(nadir)) were determined during an intravenous glucose tolerance test (IVGTT). Stepwise multiple linear regression (MLR) analysis was conducted to identify associations of FFA(0), FFA(nadir), and TIME(nadir) with ethnicity, age group, insulin measures, indexes of body composition from dual-energy X-ray absorptiometry, and measures of fat distribution from computed tomography scan. In this population, insulin(0) and AIR(g) were higher among AAs vs. EAs, whereas S(I) was lower, independent of age group. MLR analyses indicated that FFA(0) was best predicted by lean tissue mass (LTM), leg fat mass, ethnicity (lower in AAs), S(I), and insulin(0). FFA(nadir) was best predicted by FFA(0), age group, and intra-abdominal adipose tissue (IAAT). TIME(nadir) was best predicted by leg fat mass, AIR(g), and S(I). In conclusion, indexes of insulin secretion and action were associated with FFA dynamics in healthy girls and women. Lower FFA(0) among AAs was independent of insulin(0) and S(I). Whether lower FFA(0) is associated with substrate oxidation or risk for obesity remains to be determined.