The purpose of this study is to determine the effects of change in diet quality (carbohydrate restriction versus fat restriction) on body composition, fat distribution, cardiometabolic risk factors, physical function, and quality of life in aging adults with obesity.

The purpose of this study is to determine the effects of change in diet quality (carbohydrate restriction versus fat restriction) on body composition, fat distribution, cardiometabolic risk factors, physical function, and quality of life in aging adults with obesity. Data from previous studies support the hypothesis that consumption of lower-CHO, higher-fat food sources rich in high-quality proteins and essential fatty acids, such as whole eggs, has beneficial effects on metabolic health. The study will test the hypothesis that a reduced CHO higher- fat, egg-rich diet induces selective depletion of total and abdominal adiposity, preserves lean mass, and reduces inflammation and oxidative stress. In turn, these favorable changes in body composition, fat distribution, and metabolic health will confer improvements in physical function in obese, aging adults.

Results from this study will form an empirical basis for developing an easily implemented, non-pharmacologic treatment (i.e. change diet quality by incorporating more low carbohydrate, whole foods such as eggs) to prevent or reverse sarcopenia and other age-related diseases of metabolic origins.

Inclusion Criteria:

1. between 60-75 years of age,
2. have a BMI ranging from 30-40 kg/m2,
3. sedentary (<2h/wk of intentional exercise, and agree to maintain their level of activity throughout the study).

Exclusion Criteria:

1. those with uncontrolled diabetes,
2. unwilling to eat the prescribed diets,
3. recent weight change (+/- 10 lbs. in previous year),
4. history of eating disorder,
5. difficulty chewing and swallowing solid food,
6. digestive diseases,
7. cognitive impairment,
8. uncontrolled blood pressure (systolic blood pressure > 159 or diastolic blood pressure >95 mm Hg),
9. history of non-skin cancer in the last 5 years,
10. cardiovascular disease event; severe pulmonary disease; renal failure; major liver dysfunction,
11. current/recent smoker,
12. use of estrogen or testosterone replacement therapy,
13. current use of oral corticosteroids (>5 d/mth),
14. using medications for treatment of psychosis or manic-depressive illness, and
15. dependence on others for food procurement or preparation.