Meal Patterning on Weight Loss With Changes to Body Comp, Muscle and Metabolic Health

About two-thirds of adults in the United States are overweight or obese with likely adverse health consequences. A Moderate weight loss by dieting and exercise is recommended to improve health. We are interested to know whether eating dietary protein at different times of the day influences changes in body composition, muscle and indices of health. The purpose of this study is to examine the effects of within-day patterning of dietary protein intake (even vs. skewed) on energy-restriction and resistance training-induced changes in body composition, muscle size, appetite, and clinical health (including blood glucose and blood pressure).

About two-thirds of adults in the United States are overweight or obese. Obesity is associated with an increased risk of chronic disease and metabolic syndrome and a reduced physical functioning capacity, all of which contribute to disproportionately high healthcare expenditures and premature mortality. A moderate dietary energy restriction with a higher protein diet has been recommended for weight loss to prevent or improve medical complications associated with obesity as well as improve body composition, including preserving lean body mass. Emerging research indicates that the consumption of multiple high protein meals daily may be superior than only consuming one high-protein meal (typically dinner) to stimulate muscle protein synthesis throughout the day. This concept is based on research showing that the patterning of energy and protein intake influences muscle protein synthesis and whole body composition and protein retention. Very limited research exists regarding the effects of protein intake on skeletal muscle size after weight loss, and currently, no longitudinal studies have evaluated the effectiveness of consuming an even vs. skewed distribution of protein intake across meals on phenotypic changes in skeletal muscle size over the longer-term. Recent studies have also suggested that evenly distributed protein patterning may promote satiety and improve blood glucose response in healthy adult men and women. However, there is a need for controlled, longer-duration trials to investigate the effects of daily protein distribution on appetite, glucose response and metabolic syndrome after weight loss in overweight or obese adults. The goal of the proposed research is to evaluate the effects of within-day patterning of dietary protein intake (even vs. skewed) on energy-restriction and resistance training-induced changes in body composition, skeletal muscle size, appetite, glucose response, and metabolic syndrome parameters.

Eligibility Criteria:
Inclusion Criteria:

* non-smoking;
* weight stable (± 4.5 kg during previous 3 months)
* constant habitual activity patterns within last 3 months
* no acute illness
* not diabetic or have chronic diseases
* blood profile within 10% of clinical normalcy
* subjects not classified as high risk for cardiovascular disease
* no use of medications
* females who are not pregnant or lactating
* ability to travel to testing and exercise training facilities
* not claustrophobic and able to complete the muscle size testing using the magnetic resonance imager

Exclusion Criteria:

* Smoker
* weight changed within 3 months
* a history of disease or high risk of cardiovascular disease
* history of claustrophobic
* pregnant or lactating female