Comparative Effects of Three Popular Diets on Lipids, Endothelial Function, and C-Reactive Protein during Weight Maintenance

Abstract

Although popular diets focus on weight loss and their favorable biochemical and physiological effects, fewer investigations have evaluated the biological impact of these diets during weight maintenance. To study this issue, three popular diets, Atkins, South Beach and Ornish were tested in a randomized and counterbalanced, crossover study between January and December 2006. Participants completed each of the three 4-week isocaloric dietary intervention phases followed by a 4-week washout period. They were weighed weekly and caloric adjustments made if weight change exceeded 1 kg. At the completion of each dietary phase, 3-day food records were analyzed, fasting blood sampled and brachial artery reactivity testing (BART) performed.Eighteen adults completed all 3 isocaloric dietary phases. During the South Beach and Ornish maintenance phase there were significant reductions in low density lipoprotein cholesterol (LDL-C) (11.8% [P=0.01], 16.6% [P=0.0006], respectively) compared to pre-diet baseline. Moreover, in contrast to the Atkins maintenance phase, significant reductions in LDL-C and apolipoprotein B levels were observed after the South Beach (P=0.003, P=0.05, repeated measures ANOVA) and Ornish maintenance phase (P=0.0004, P=0.006, repeated measures ANOVA). Brachial artery testing revealed an inverse correlation between flow-mediated vasodilatation and intake of saturated fat (r= −0.33; p=0.016). These data suggest that during weight maintenance, less favorable biological effects are observed during a simulated, high fat Atkins diet when compared to the South Beach and Ornish diet. The findings support additional study in subjects with visceral obesity and the metabolic syndrome, in whom an increased risk of coronary disease at baseline may be accentuated with chronic consumption of a diet that exhibits unfavorable effects on lipids and endothelial function.

Transcriptome profiling from adipose tissue during a low-calorie diet reveals predictors of weight and glycemic outcomes in obese, nondiabetic subjects

“…Among those 773 participants, 548 (71%) completed this 6-mo weight-maintenance intervention. The dropout rates (18% for the LCD and 29% for weight maintenance) have been discussed in detail previously (18) and are in line with reports from other dietary studies (20)(21)(22). CID, clinical investigation day; DiOGENES, Diet, Obesity and Genes; LCD, low-calorie diet; QC, quality control; RT-qPCR, reverse transcription quantitative polymerase chain reaction; RNAseq, RNA sequencing.…”

Dietary carbohydrate restriction improves insulin sensitivity, blood pressure, microvascular function, and cellular adhesion markers in individuals taking statins

“…In addition to blood pressure, we examined vascular health using two other non-invasive techniques, namely FMD and FBF. Prior work has shown variable effects of a CRD on VEF [25][26][27]. In our previous work we demonstrated that consumption of a CRD for 12 weeks, compared with a low-fat diet, improved FMD assessed postprandially following a high-fat meal [6].…”

Effects of Weight Loss and Long-Term Weight Maintenance With Diets Varying in Protein and Glycemic Index on Cardiovascular Risk Factors

“…24 -28 However, little is known about the effects of subsequent non-energy-restricted diets varying in protein content and glycemic index on these end points. Previous studies comparing different diets under ad libitum conditions were small and of short duration 29,30 or included patients with other comorbidities such as diabetes mellitus. 8 Moreover, the design of the DiOGenes study allowed a clear separation of the effects of caloric restriction from those of dietary composition.…”