Effect of weight loss on the postprandial response to high-fat and high-carbohydrate meals in obese women

Abstract

Objective: To assess the effect of weight loss on the plasma lipid and remnant-like lipoprotein cholesterol (RLPc) response to a high-fat or a high-carbohydrate meal in a population of obese women. Design: Nutritional intervention study. Subjects: Sixteen obese women (mean body mass index (BMI): 37.675 kg/m 2 ). Methods: Subjects were asked to follow an energy-restricted diet (800 kcal/day) for 7 weeks, followed by a 1-week maintenance diet. Before and after weight loss, each participant was given (in random order) two iso-energetic meals containing either 80% fat and 20% protein (the high-fat meal) or 80% carbohydrate and 20% protein (the high-carbohydrate meal). Blood samples were collected over the following 10-h period. A two-way analysis of variance with repeated measures was used to assess the effect of the meal and postprandial time on biological variables and postprandial responses (notably RLPc levels). Results: Weight loss was associated with a significant decrease in fasting triglyceride (P ¼ 0.0102), cholesterol (Po0.0001), lowdensity lipoprotein cholesterol (P ¼ 0.0003), high-density lipoprotein-cholesterol (P ¼ 0.0009) and RLPc (P ¼ 0.0015) levels. The triglyceride response to the high-fat meal was less intense after weight reduction than before (interaction Po0.002). This effect persisted after adjustment on baseline triglyceride levels. The triglyceride response to the high-carbohydrate meal was biphasic (i.e. with two peaks, 1 and 6 h after carbohydrate intake). After adjustment on baseline values, weight reduction was associated with a trend towards a reduction in the magnitude of the second triglyceride peak (interaction Po0.054). In contrast, there was no difference in postprandial RLPc responses before and after weight loss, again after adjustment on baseline levels. Conclusion: Our data suggest that weight loss preferentially affects postprandial triglyceride metabolism.

Effects of Adiposity on Plasma Lipid Response to Reductions in Dietary Saturated Fatty Acids and Cholesterol

“…Volek et al (39) found that obese women who lost a modest amount of weight on either a low-CHO diet (22.96 6 1.45 kg) or a low-fat diet (21.06 6 2.07 kg) significantly improved the AUC for TG following a fat-rich meal (229 and 225%, respectively). Insulin sensitivity only improved after the low-CHO diet; however, fasting insulin levels in both diets were lower than the post-weight loss amount reported by James et al Dallongeville et al (36) conducted a similar intervention study to assess the lipid response to a high-fat or high-CHO meal before and after weight loss. Obese women followed an energy-restricted diet (800 kcal/d) for 7 wk and reduced their body weight by~10% (P < 0.0001) with a concomitant decrease in TG (P = 0.0102), TC (P < 0.0001), LDL-C (P = 0.0003), and HDL-C (P = 0.0009).…”

“…Losing weight would be expected to contribute to a normalization of lipid metabolism. Numerous studies have reported beneficial effects of weight reduction on the postprandial lipid response in overweight individuals (36)(37)(38)(39). However, obese and insulin-resistant participants may require more aggressive dietary interventions to alter the lipid response, specifically, a greater weight reduction.…”

Definition of Postprandial Lipaemia

“…For example, the response of chylomicrons (CM) to a fat meal can vary by up to 60% depending on the amount and quality of fat, carbohydrate and protein content [4,[5][6][7]. Additionally, chronic consumption of low energyhigh carbohydrate diets, often used for weight loss, has a tendency to exaggerate plasma TG levels [8][9][10]. Furthermore, exaggerated PPL is often present in patients with coronary heart disease (CHD) [11][12][13][14] and conditions associated with an increased risk of cardiovascular disease such as hypertension [15,16], obesity [15,17], diabetes mellitus [18,19], metabolic syndrome [20,21] and familial hypercholesterolaemia [22][23][24][25].…”

The effect of modifying dietary protein and carbohydrate in weight loss on arterial compliance and postprandial lipidemia in overweight women with polycystic ovary syndrome

“…The optimal treatment for weight loss in PCOS is unknown, with different macronutrient compositions promoted (17). In the general population, weight loss improves arterial compliance (18) and postprandial lipidemia (19,20), and increased protein meals (21) and reduced carbohydrate weight-loss diets (22) improve endothelial function and postprandial lipidemia. Although this provides preliminary evidence that modifying diet composition may improve postprandial lipidemia and vascular function, the effect of weight loss or diet composition on these factors in PCOS is currently unknown.…”

“…A two-unit decrease in SAE was additionally reported as a significant predictor for cardiovascular events (odds ratio 1.50 95% confidence interval [CI] 1.19-1.88, P<.001) (15), suggesting our observed SAE improvement (1.5-units) is clinically relevant. Weight loss improves arterial compliance through modulating insulin resistance, inflammation, vasoactive substances, blood pressure (BP), or lipid metabolism, and improves postprandial lipidemia through improvements in insulin resistance stimulating lipoprotein lipase activity and triglyceride clearance (19,20). Although this suggests weight loss-related improvements in arterial compliance, and postprandial lipids are related to insulin resistance improvements, previous findings of reduced arterial compliance in insulin resistance-matched women with and without PCOS (4) suggests a deleterious effect of PCOS per se.…”