Comparison of Medifast's 5 & 1 Plan to a Food-based Plan of Equal Calories

Efficacy of Medifast's 5 & 1 Program Compared to a Food-based Diet After a Period of Weight Loss and Weight Maintenance

Portion-controlled meal replacements have been shown to be an effective weight control strategy in overweight and obese individuals. Thus, the investigators plan to evaluate the effect of Medifast's 5 & 1 program compared to an food-based diet plan of equal calories on the following indices: weight loss and maintenance of weight loss, satiety during weight loss, changes in biochemical markers of inflammation and oxidative stress following weight loss, and compliance and retention rates.

Inclusion Criteria:

• Adult males and females (age between 18 and 65)
• Obese (BMI >=30.0 kg/m2 and <50.0 kg/m2)
• Non-smokers
• No known food allergies to wheat, gluten, soy or nuts
• <14 alcoholic beverages per week
• Willing and able to give informed consent
• Not currently using appetite-affecting medications (e.g SSRIs, steroids, Ritalin)
• Not pregnant or lactating
• Primary care physician's permission for weight loss, normal labs and electrocardiogram (EKG) within past 1 year

Exclusion Criteria:

• Actively dieting
• Eating Attitudes Test (EAT) > 30
• Chronic uncontrolled health problems (not including obesity or diabetes)
• Pacemaker or other internal electronic medical device
• Schizophrenia, history of bipolar disorder, current Major Depressive Disorder
• Dependence on alcohol or sedative-hypnotic drugs (e.g. benzodiazepines)
• Cognitive impairment severe enough to preclude informed consent
• Taking weight loss or appetite-suppressant medications
• Taking appetite affecting medications (e.g. SSRIs, steroids, Ritalin)
• Food allergies to wheat, gluten, soy, or nuts
• Pregnant or lactating