Genetics contribute to variability in individual response to weight-loss interventions. The objective of this study was to determine the efficacy of a commercially available exercise and weight-loss program and whether alignment of diet to genotype related to lipid metabolism promotes greater success.

Sedentary women with obesity (n = 63) had genotype (FABP2rs1799883, PPARG2rs1801282, ADRB3rs4994C3, ADRB2rs1042713, rs1042714) determined using a direct?to?consumer genetic screening kit purported to promote greater weight?loss success through dietary recommendations based on these genes. Participants were randomly assigned to follow a moderate carbohydrate (MC) or lower carbohydrate (LC) hypo?energetic diet that aligned (A) or did not align (NA) with genotype for 24 weeks while participating in a resistance training and walking program.

Data were analysed by general linear model repeated measures adjusted for baseline variables and are presented as mean (95% confidence interval) changes from baseline. Participants in the LC group experienced greater improvements (p = 0.051, ηp 2 = 0.025) in % changes in body composition (weight: MC −3.32 [−1.4, −5.2], LC −5.82 [−4.1, −7.6]; fat mass: MC −7.25 [−3.2, −11.2], LC −10.93 [−7.3, −14.5]; fat?free mass: MC −0.32 [1.4, −2.0], LC −1.48 [0.7, −3.0]; and body fat %: MC −4.19 [−1.6, −6.8], LC −5.60 [−3.3, −7.9] %). No significant differences were observed between genotype groups.

(weight: A −5.00 [−3.3, −6.7], NA −4.14 [−2.2, −6.1]; fat mass: A −10.15 [−7.0, −13.6], NA −8.02 [−4.0, −12.0]; fat?free mass: A −1.23 [0.3, −2.8], NA −0.56 [1.12, −2.3]; and body fat: A −5.28 [−3.0, −7.6], NA −4.51 [−1.9, −7.1] %). Adherence to this exercise and weight?loss program promoted improvements in body composition and health outcomes. While individuals following the LC diet experienced greater benefits, alignment of these diets to this genetic profile did not promote greater health outcomes.

 The Diet And Exercise

The group has conducted a number of studies evaluating the effects of various diet and exercise interventions on weight loss as part of a Women's Health & Fitness Initiative. These studies generally found that participating in a circuit?style resistance training program while following a slightly hypo?energetic, low fat and moderately higher protein diet promoted fat loss while maintaining fat free mass and resting energy expenditure (REE).

Additionally, adherence to the moderately higher protein versions of this diet while following the circuit?style resistance training program promoted more favourable changes in markers of metabolic syndrome. They also observed significant changes in exercise capacity which is relevant as cardiopulmonary fitness is a known to be associated with chronic disease risk and related mortality.

The purpose of the present investigation was to (1) determine the efficacy of two moderately higher protein diets that varied in carbohydrate and fat content on changes in weight, body composition, exercise capacity and biomarkers of health in sedentary women with obesity participating in a circuit?style resistance training program and (2) determine if these tested diets would result in greater health outcomes when aligned by the genetic profile within direct?to?consumer genetic screening kit previously tested by Dopler?Nelson et al.