Effects of Energy and Macronutrient Cycling on Weight Loss, Body Composition, and Markers of Health in Obese Women Participating in a Resistance-Based Exercise Program

Abstract

To determine whether adherence to a repeating 30-d non-linear diet intervention while participating in a supervised exercise program that includes resistance-exercise would promote weight and fat loss without weight loss plateau and whether alterations in carbohydrate and protein intake may influence results.Methods: Fifty sedentary and obese pre-menopausal females (35.2±7.6 years; 88.7±18 kg, 32.6±6 kg/m 2 , 42.5±4.2% fat) were randomly assigned to an exercise-only (EX) or EX plus diets containing higher proportions of carbohydrate or protein. Diets were hypoenergetic for 30-d ( 7-d at 1,200 kcals/d, 21-d at 1,500 kcal/d), more isoenergetic for 30-d (2,200 kcals/d), and repeated three times during a 24-wk intervention. Diets were either 45:30:24 (HCD) or 30:45:25 (HPD) carbohydate:protein:fat. All participants performed 30-min resistance exercise (3 d/wk) and a brisk walking program (3 d/wk). Data were analyzed by general linear model (GLM) statistics with repeated measures and presented as mean changes from baseline (mean [UL, LL]).

Comparison of Two Diet and Exercise Approaches on Weight Loss and Health Outcomes in Obese Women

“…However, the CV intervention led to a greater decrease in fat mass and a greater increase in lean mass, resulting in a significant improvement in body fat percentage. Present findings agree with previous studies conducted by our group [10][11][12][13][14][15][16][18][19][20][21][22], which found that individuals participating in this program observed significant reductions in body mass, fat mass, BMI, and waist circumference while preserving lean body mass and resting energy expenditure. Additionally, that adherence to a more structured diet plan promoted less energy intake with a greater proportion of dietary protein intake [17].…”

“…Consistent with current findings, adherence to the WW program has been reported to promote reductions in body weight, fat mass, BMI, and waist circumference, though the preservation of lean body mass has not been demonstrated [40,41]. Both groups lost over 5% body weight in the 16-week period, which agrees with previous research evaluating adherence to these diets for 12 weeks to 12 months in duration [18,21,[42][43][44][45][46][47][48][49][50][51]. This level of weight loss can be defined as clinically meaningful if maintained one year after treatment [52].…”

“…Neither group experienced changes in muscular strength nor lower body muscular endurance. Other trials from our lab evaluating changes in muscular strength and cardiovascular fitness following participation in the CV program have observed significant increases in upper and lower body 1RM strength [12,13,[15][16][17][18][19][20][21].…”

“…Previous research from our lab utilizing similar diet and exercise interventions was utilized to set the a priori power calculation (>0.80), based upon the observed change in fat mass between diet groups [12,13,[15][16][17]21], and revealed that to detect meaningful changes in fat mass (~2 kg) a sample size of 15-20 per group was needed. Those who completed at least 80% of the training sessions were included in the analysis.…”

“…An abundance of research from our lab has reported effective weight and fat loss while also preserving fat-free mass and resting energy expenditure by utilizing a hypoenergetic highprotein diet combined with a supervised circuit-style resistance program in both pre-and post-menopausal women [8][9][10]. We have also shown improvements in markers of health and fitness with this protocol [11][12][13][14][15][16][17][18][19][20][21][22].…”