Abstract P306: Effect of A Low-Carbohydrate Diet on Weight and Cardiovascular Risk Factors: A Randomized Controlled Trial

Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Lydia A Bazzano ◽  
Kristi Reynolds ◽  
Tian Hu ◽  
Lu Yao ◽  
Calynn Bunol ◽  
...  

There are few studies examining the effects of a diet low in carbohydrates on cardiovascular disease (CVD) risk factors in the long term, particularly in contrast to the current dietary recommendations for decreased fat intake to reduce risk of CVD. We recruited 148 study participants with a body mass index (BMI) of 30–45 kg/m2, who were free of diabetes, CVD and kidney disease at baseline and randomly assigned them (74 in each group) to either a low carbohydrate diet (<40 g/day) or a low fat (<30% energy from fat, <10% from saturated fat) diet. Participants met with a study dietitian weekly for the first month then in group settings bi-weekly for 5 months then monthly for the next 6 months. Each group was provided the same behavioral curriculum related to diet emphasizing portion control and eating habits. Two 24-hour dietary recalls were conducted at each clinic visit (0, 3, 6 and 12 months of intervention). The primary outcome measures were weight, body composition, lipids, blood pressure, and glucose. Mean age of participants was 46.8 years, mean BMI was 35.4 kg/m2; 11.5% were men, and 51% were African-American. Of the study participants, 60 in the low fat group (81.1%) and 59 in the low carbohydrate group (79.7%) completed the entire intervention. At 12 months, mean total energy intake on the low carbohydrate diet was 1,448 kcal/day with 23.6% from protein, 40.7% from fats, and 34.0% from carbohydrate versus 1,527 kcal/day with 18.6% from protein, 29.8% from fats, and 50.0% from carbohydrate on the low fat diet. Compared to low fat diets, over 12 months the low carbohydrate group had greater reductions in weight (net change −3.62 kg, p<0.001), fat mass (−2.83 kg, p<0.0001), waist circumference (−1.79 cm, p=0.03), triglycerides (−12.83 mg/dL, p=0.05), and a greater increase in high density lipoprotein cholesterol (HDL-C, 6.74 mg/dL, p<0.001). There were no differences in net changes between diets for total cholesterol, low density lipoprotein cholesterol, blood pressure, glucose, creatinine, or lean body mass. Our findings document that a low carbohydrate diet was more effective for weight loss than a low fat diet, and did not have significant adverse effects on cardiovascular risk factors. In contrast, the low carbohydrate diet improved HDL-C and triglycerides as compared to a low fat diet. Restricting carbohydrates is an effective method of weight loss and could be recommended for persons with and without increased CVD risk factors who need to lose weight.

Circulation ◽  
2013 ◽  
Vol 127 (suppl_12) ◽  
Author(s):  
Tian Hu ◽  
Kristi Reynolds ◽  
Lu Yao ◽  
Calynn Bunol ◽  
Yanxi Liu ◽  
...  

The long-term effects of low-carbohydrate diets versus low-fat diets on endothelial dysfunction and insulin resistance are unclear. A total of 148 study participants with a body mass index of 30 - 45 kg/m2 (Mean: 35.4 kg/m2) who were free of diabetes, cardiovascular diseases and kidney disease were recruited. The participants were randomly assigned to either a low-carbohydrate diet (<40 g/day; N=75) or a low fat (<30% energy from fat, <10% from saturated fat; N=73) diet. Two 24-hour dietary recalls were conducted at each clinic visit (0, 3, 6 and 12 months of intervention). Participants met with a study dietitian weekly for the first month followed by group settings bi-weekly for 5 months and monthly for the last 6 months. Each group was provided the same behavioral curriculum related to diet emphasizing portion control and eating habits. Biomarkers for endothelial function and insulin resistance included E-selectin, Intercellular Adhesion Molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), Insulin-like growth Factor-1 (IGF-1), serum insulin, and glucose. Mixed-effect regression models including group, time and their interaction were used to analyze the data. Of the study participants, 60 in the low-fat group (81.1%) and 59 in the low-carbohydrate group (79.7%) completed the entire intervention. The mean age was 46.8 years, 88.5% were women and 55.1% were African-Americans. The low-carbohydrate group lost approximately 3.5 kg more body weight than did the low-fat group (P= 0.002) on average. Compared to the low-fat diet, the low-carbohydrate diet resulted in greater reductions in E-selectin (net change: -4.5, -4.3, and -3.8 ng/mL at 3, 6, and 12 months, respectively; overall P= 0.002) and ICAM-1 (net change: -7.3, -10.4, and -16.8 ng/mL at 3, 6, and 12 months, respectively; overall P= 0.06). There was no significant change in any other markers. Our findings suggest that the low-carbohydrate is at least as effective as the low-fat diet at improving endothelial dysfunction and insulin resistance.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 563-563
Author(s):  
Kelsey Schmidt ◽  
Gail Cromer ◽  
Maggie Burhans ◽  
Jessica Kuzma ◽  
Derek Hagman ◽  
...  

Abstract Objectives Dairy fat has been hypothesized to promote cardiovascular disease (CVD) due to its high saturated fat content, contributing to recommendations to consume low-fat dairy foods. However, emerging evidence indicates that dairy fat does not negatively impact CVD risk, particularly when consumed in foods with a complex matrix. Though, few trials have directly compared the effect of low-fat versus full-fat dairy foods. Therefore, we aimed to test the effects of diets rich in low-fat or full-fat dairy on CVD risk factors, compared to a limited dairy diet. We hypothesized that diets rich in dairy would not impact CVD risk factors. Methods Seventy-two participants with the metabolic syndrome completed a 4-week wash-in period; limiting their dairy intake to ≤ 3 servings of skim milk per week. Participants were then randomized to either continue the limited dairy diet or switch to a diet containing 3.3 servings per day of either low-fat or full-fat milk, yogurt, and cheese for 12-weeks. The plasma lipid profile and blood pressure were assessed before and after the intervention period. Results In the per protocol analysis (n = 66), there was no intervention effect on fasting plasma total-, low-density lipoprotein-, and high-density lipoprotein-cholesterol, triglycerides, free fatty acids, or cholesterol content in 38 isolated lipoprotein fractions (p &gt; 0.1 for all variables). There was also no intervention effect on diastolic blood pressure. There was a significant difference among the diet interventions for systolic blood pressure (P = 0.045), with a trend for a decrease in the low-fat dairy diet compared to the limited dairy diet in post hoc testing after adjustment for multiple testing. Conclusions In individuals with the metabolic syndrome, consuming 3.3 servings of dairy per day, regardless of fat content, did not affect blood lipids and modestly improved blood pressure compared to a diet virtually free of dairy. This provides further evidence that dairy fat, when consumed as part of complex whole foods, does not significantly impact CVD risk factors. Funding Sources This work was supported by the National Dairy Council, Dairy Farmers of Canada, the Dutch Dairy Association, Dairy Australia, and the French Dairy Interbranch Organization.


2004 ◽  
Vol 107 (4) ◽  
pp. 365-369 ◽  
Author(s):  
Matthew J. SHARMAN ◽  
Jeff S. VOLEK

In recent years, it has become apparent that low-grade vascular inflammation plays a key role in all stages of the pathogenesis of atherosclerosis. Weight loss has been shown to improve blood inflammatory markers; however, it is unknown if weight-loss diets varying in macronutrient composition differentially affect inflammatory responses. The primary purpose of the present study was to compare a very-low-carbohydrate diet and a low-fat weight-loss diet on inflammatory biomarkers in overweight men. In a randomized cross-over design, 15 overweight men (body fat, >25%; body mass index, 34 kg/m2) consumed two experimental weight-loss diets for two consecutive 6-week periods: a very-low-carbohydrate diet (<10% energy via carbohydrate) and a low-fat diet (<30% energy via fat). Both the low-fat and the very-low-carbohydrate diets resulted in significant decreases in absolute concentrations of hsTNF-α (high-sensitivity tumour necrosis factor-α), hsIL-6 (high-sensitivity interleukin-6), hsCRP (high-sensitivity C-reactive protein) and sICAM-1 (soluble intercellular cell-adhesion molecule-1). There was no significant change in absolute sP-selectin (soluble P-selectin) concentrations after either diet. Normalized inflammatory values represented as the delta change per 1 kg reduction in body mass showed a significant difference between the two diets only for sP-selectin (P<0.05). In summary, energy-restricted low-fat and very-low-carbohydrate diets both significantly decreased several biomarkers of inflammation. These data suggest that, in the short-term, weight loss is primarily the driving force underlying the reductions in most of the inflammatory biomarkers.


Circulation ◽  
2013 ◽  
Vol 127 (suppl_12) ◽  
Author(s):  
Tian Hu ◽  
Kristi Reynolds ◽  
Lu Yao ◽  
Calynn Bunol ◽  
Yanxi Liu ◽  
...  

The long-term effects of low-carbohydrate diets on hormones related to appetite are unclear. We recruited a total of 148 study participants with a body mass index of 30 - 45 kg/m2 (Mean: 35.4 kg/m2) who were free of diabetes, cardiovascular diseases and kidney disease. The participants were randomly assigned to either a low-carbohydrate diet (<40 g/day; N=75) or a low fat (<30% energy from fat, <10% from saturated fat; N=73) diet. Two 24-hour dietary recalls were conducted at each clinic visit (0, 3, 6 and 12 months of the intervention). Participants met with a study dietitian weekly for the first month followed by group settings bi-weekly for 5 months then monthly for the subsequent 6 months. Each group was provided the same behavioral curriculum related to diet emphasizing portion control and eating habits. Total ghrelin and peptide YY were determined using radioimmunoassay methods. Of the study participants, 60 in the low-fat group (81.1%) and 59 in the low-carbohydrate group (79.7%) completed the entire intervention. The mean age was 46.8 years, 88.5% were women and 55.1% were African-Americans. The low-carbohydrate group lost approximately 3.5 kg more body weight than did the low-fat group (P value: 0.002) over the course of the intervention. Both diets decreased total peptide YY and ghrelin. Compared to low-fat diets, the low-carbohydrate diet resulted in a significantly greater decrease in total peptide YY at 6 (Net change: -6.8 ph/mL; P value: 0.04) and 12 months (Net change: -10.6 ph/mL; P value: 0.02). The changes in total ghrelin were not significantly different throughout the study. Our findings suggest that the low-carbohydrate diet did not result in a greater loss of appetite, compared to the low-fat diet.


2010 ◽  
Vol 170 (2) ◽  
pp. 136 ◽  
Author(s):  
William S. Yancy ◽  
Eric C. Westman ◽  
Jennifer R. McDuffie ◽  
Steven C. Grambow ◽  
Amy S. Jeffreys ◽  
...  

2010 ◽  
Vol 34 (8) ◽  
pp. 1239-1242 ◽  
Author(s):  
P A Essah ◽  
J R Levy ◽  
S N Sistrun ◽  
S M Kelly ◽  
J E Nestler

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