Comparison of effects of diet versus exercise weight loss regimens on LDL and HDL particle size in obese adults

<p>Abstract</p> <p>Background</p> <p>Obesity is associated with an atherogenic lipid profile characterized by a predominance of small LDL and HDL particles. Weight loss, by dietary restriction or exercise, increases LDL particle size. Whether these interventions can augment HDL size <it>in conjunction </it>with LDL size remains unknown.</p> <p>Objective</p> <p>This study compared the effects of alternate day fasting (ADF), calorie restriction (CR), and endurance exercise on LDL and HDL particle size in overweight and obese subjects.</p> <p>Methods</p> <p>In a 12-week parallel-arm trial, adult subjects (n = 60) were randomized to 1 of 4 groups: 1) ADF (75% energy restriction for 24-h alternated with ad libitum feeding for 24-h), 2) CR (25% energy restriction every day), 3) exercise (moderate intensity training 3 x/week), or 4) control.</p> <p>Results</p> <p>Body weight was reduced (<it>P </it>< 0.001) by ADF, CR, and exercise (5.2 ± 1.1%, 5.0 ± 1.4%, 5.1 ± 0.9%, respectively). Plasma LDL cholesterol decreased (<it>P </it>< 0.05) with ADF (10 ± 4%) and CR (8 ± 4%), whereas HDL cholesterol increased (<it>P </it>< 0.05) with exercise (16 ± 5%). Integrated LDL particle size was augmented (<it>P </it>= 0.01) by ADF and CR. The proportion of small LDL particles decreased (<it>P </it>= 0.04) with ADF only, and the proportion of large HDL particles increased (<it>P </it>= 0.03) with exercise only.</p> <p>Conclusion</p> <p>These results indicate that dietary restriction increases LDL particle size, while endurance training augments HDL particle size, with minimal weight loss. None of these interventions concomitantly increased both LDL and HDL particle size, however.</p

Dietary and physical activity adaptations to alternate day modified fasting: implications for optimal weight loss

<p>Abstract</p> <p>Background</p> <p>Alternate day modified fasting (ADMF) is an effective strategy for weight loss in obese adults.</p> <p>Objective</p> <p>The objective of this study was to examine the dietary and physical activity adaptations that occur during short-term ADMF, and to determine how these modulations affect rate of weight loss.</p> <p>Methods</p> <p>Sixteen obese subjects (12 women/4 men) completed a 10-week trial consisting of 3 phases: 1) 2-week control phase, 2) 4-week ADMF controlled feeding phase, and 3) 4-week ADMF self-selected feeding phase.</p> <p>Results</p> <p>Body weight decreased (<it>P </it>< 0.001) by 5.6 ± 1.0 kg post-treatment. Energy intake on the fast day was 26 ± 3% of baseline needs (501 ± 28 kcal/d). No hyperphagic response occurred on the feed day (95 ± 6% of baseline needs consumed, 1801 ± 226 kcal/d). Daily energy restriction (37 ± 7%) was correlated to rate of weight loss (<it>r </it>= 0.42, <it>P </it>= 0.01). Dietary fat intake decreased (36% to 33% of kcal, <it>P </it>< 0.05) with dietary counseling, and was related to rate of weight loss (<it>r </it>= 0.38, <it>P </it>= 0.03). Hunger on the fast day decreased (<it>P </it>< 0.05) by week 2, and remained low. Habitual physical activity was maintained throughout the study (fast day: 6416 ± 851 steps/d; feed day: 6569 ± 910 steps/d).</p> <p>Conclusion</p> <p>These findings indicate that obese subjects quickly adapt to ADMF, and that changes in energy/macronutrient intake, hunger, and maintenance of physical activity play a role in influencing rate of weight loss by ADMF.</p

Effects of weight loss via high fat vs. low fat alternate day fasting diets on free fatty acid profiles

Cardiovascular disease risk is associated with excess body weight and elevated plasma free fatty acid (FFA) concentrations. This study examines how an alternate-day fasting (ADF) diet high (HF) or low (LF) in fat affects plasma FFA profiles in the context of weight loss, and changes in body composition and lipid profiles. After a 2-week weight maintenance period, 29 women (BMI 30–39.9 kg/m2) 25–65 years old were randomized to an 8-week ADF-HF (45% fat) diet or an ADF-LF (25% fat) diet with 25% energy intake on fast days and ad libitum intake on feed days. Body weight, BMI and waist circumference were assessed weekly and body composition was measured using dual x-ray absorptiometry (DXA). Total and individual FFA and plasma lipid concentrations were measured before and after weight loss. Body weight, BMI, fat mass, total cholesterol, LDL-C and triglyceride concentrations decreased (P < 0.05) in both groups. Total FFA concentrations also decreased (P < 0.001). In the ADF-LF group, decreases were found in several more FFAs than in the ADF-HF group. In the ADF-HF group, FFA concentrations were positively correlated with waist circumference. Depending on the macronutrient composition of a diet, weight loss with an ADF diet decreases FFA concentrations through potentially different mechanisms

Improvements in vascular health by a low-fat diet, but not a high-fat diet, are mediated by changes in adipocyte biology

<p>Abstract</p> <p>Background</p> <p>Low-fat (LF) and high-fat (HF) weight loss diets improve brachial artery flow-mediated dilation (FMD) in obese individuals, although results are conflicting. Moreover, the role that adipose tissue plays in mediating these diet-related effects are unknown.</p> <p>Objective</p> <p>This study examined how modulations in FMD by HF and LF diets relate to changes in adipocyte parameters.</p> <p>Design</p> <p>Obese subjects (n = 17) were randomized to a HF diet (60% kcal as fat) or a LF diet (25% kcal as fat) for 6 weeks. Both groups were restricted by 25% of energy needs.</p> <p>Results</p> <p>Body weight decreased (<it>P <</it>0.05) in both groups (HF: -6.6 ± 0.5 kg, LF: -4.7 ± 0.6 kg). Fat mass and waist circumference were reduced (<it>P <</it>0.05) in the LF group only (-4.4 ± 0.3 kg; -3.6 ± 0.8 cm, respectively). FMD improved (<it>P <</it>0.05) in the LF group (7.4 ± 0.8% to 9.8 ± 0.8; 32% increase) and was impaired in the HF group (8.5 ± 0.6% to 6.9 ± 0.7; 19% reduction). Increases in plasma adiponectin (<it>P <</it>0.05, 16 ± 5%), and decreases in resistin (<it>P <</it>0.05, -26 ± 11%), were shown by the LF diet only. Greater decreases in leptin were observed with LF (-48 ± 9%) versus HF (-28 ± 12%) (<it>P <</it>0.05, diet × time). Increased FMD by the LF diet was associated with increased adiponectin, and decreased fat mass, waist circumference, leptin, and resistin.</p> <p>Conclusion</p> <p>Beneficial modulations in vascular health by LF diets may be mediated by improvements in adipocyte parameters.</p

Alternate Day Fasting with a High Fat Versus Low Fat Diet for Weight Loss and Cardio-Protection

A randomized control trial examining the effects of alternate day fasting (ADF) with a high fat (HF) or low fat (LF) background diet on body weight and coronary heart disease (CHD) risk in obese humans was conducted over 10 weeks. Obese subjects were randomized to either an ADF-HF (45% fat) group or ADF-LF (25% fat) group. The 10-week study consisted of a 2-week baseline weight maintenance period, followed by an 8-week weight loss period. Food was provided to all subjects during the 10-week trial. During each study week, subjects came to the Human Nutrition Research Unit for body weight, body composition, waist circumference, and blood pressure measurements. At week 1, 3, and 10, vascular function, plasma lipids, and plasma adipokines were assessed. Results reveal that the ADF-HF diet is equally as effective as an ADF-LF diet in helping obese subjects lose weight and improve CHD risk factors. Body weight reductions were comparable between the ADF-HF diet and the ADF-LF diet, with no differences between groups. Similar decreases in fat mass were also observed for the ADF-HF and ADF-LF groups, with retention of lean mass. Reductions in several key biomarkers for CHD risk, such as total cholesterol, LDL cholesterol, and triacylglycerols, were also comparable between the HF and LF diet regimens. Moreover, the ADF-HF diet was as effective as the ADF-LF intervention at increasing LDL particle size, elevating the proportion of large LDL particles, and decreasing the proportion of small LDL particles. HDL particle size and distribution were not affected by either diet. As for endothelial function, ADF-LF diets increased brachial artery flow mediated dilation (FMD) while ADF-HF diets decreased FMD. Both intervention groups demonstrated increases in adiponectin and decreases in leptin and resistin. However, only adiponectin was positively correlated with FMD in the ADF-LF group. Taken together, these data suggest that individuals who typically consume HF foods do not need to lower the fat content of their diet to experience the benefits of ADF

Improvements in LDL particle size and distribution by short-term alternate day modified fasting in obese adults

Alternate day modified fasting (ADMF) beneficially modulates several indicators of CHD risk, but its effects on LDL particle size have never been tested. Accordingly, we examined the effects of ADMF on LDL particle size and distribution in obese adults. Sixteen obese subjects participated in a 10-week trial with three consecutive phases: (1) 2-week control phase; (2) 4-week ADMF controlled feeding phase; (3) 4-week ADMF self-selected feeding phase. After 8 weeks of diet, body weight and waist circumference were reduced (P,0·05) by 5·6 (SEM 0·9) kg and 4·0 (SEM 0·9) cm, respectively. LDL-cholesterol and TAG concentrations decreased (P,0·05) by 25 (SEM 10)% and 32 (SEM 6)%, respectively. Peak LDL particle size increased (P,0·05) from 266 (SEM 1) to 268 (SEM 1)Ȧ. Additionally, the proportion of small LDL particles decreased (P,0·05) from 13 (SEM 2)% to 9 (SEM 3)%, while the proportion of large LDL particles increased (P,0·05) from 68 (SEM 4)% to 76 (SEM 4)% post-treatment. These findings suggest that ADMF is an effective diet strategy for increasing LDL particle size and decreasing the proportion of small, dense LDL particles in obese adults

Improvement in coronary heart disease risk factors during an intermittent fasting/calorie restriction regimen: Relationship to adipokine modulations

BACKGROUND: The ability of an intermittent fasting (IF)-calorie restriction (CR) regimen (with or without liquid meals) to modulate adipokines in a way that is protective against coronary heart disease (CHD) has yet to be tested. OBJECTIVE: Accordingly, we examined the effects of an IFCR diet on adipokine profile, body composition, and markers of CHD risk in obese women. METHODS: Subjects (n = 54) were randomized to either the IFCR-liquid (IFCR-L) or IFCR-food based (IFCR-F) diet for 10 weeks. RESULTS: Greater decreases in body weight and waist circumference were noted in the IFCR-L group (4 ± 1 kg; 6 ± 1 cm) versus the IFCR-F group (3 ± 1 kg; 4 ± 1 cm). Similar reductions (P < 0.0001) in fat mass were demonstrated in the IFCR-L (3 ± 1 kg) and IFCR-F group (2 ± 1 kg). Reductions in total and LDL cholesterol levels were greater (P = 0.04) in the IFCR-L (19 ± 10%; 20 ± 9%, respectively) versus the IFCR-F group (8 ± 3%; 7 ± 4%, respectively). LDL peak particle size increased (P < 0.01) in the IFCR-L group only. The proportion of small LDL particles decreased (P < 0.01) in both groups. Adipokines, such as leptin, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and insulin-like growth factor-1 (IGF-1) decreased (P < 0.05), in the IFCR-L group only. CONCLUSION: These findings suggest that IFCR with a liquid diet favorably modulates visceral fat and adipokines in a way that may confer protection against CHD