Identifying a simple dietary recommendation for weight loss and metabolic health may demonstrate potential for a simple public health message to impact coronary heart disease (CHD) prevention and metabolic syndrome. In a randomized clinical trial, the investigators propose to compare the efficacy of two intervention approaches to dietary change for CHD prevention among persons with metabolic syndrome. The two approaches are 1) the AHA Dietary Guidelines; and 2) a simple dietary change condition that focuses on increasing fiber. The investigators hypothesize that a message promoting high fiber intake may be the simple message that has potential to produce broad impact.

The investigators will recruit 240 overweight and obese adults from a primary care setting who meet diagnostic criteria for metabolic syndrome. The efficacy of the two dietary change interventions will be compared in a randomized controlled trial, with 120 patients per group. The two approaches are 1) the American Heart Association (AHA) Dietary Guidelines; and 2) a simple dietary change condition that focuses on increasing fiber. Patients in both conditions will receive intensive dietary instruction for 3 months, followed by a 9 month maintenance phase. Both conditions will receive dietary instructions via individual and group sessions led by registered dietitians. Assessments, including diet, anthropometrics, blood pressure, fasting blood glucose, glycosylated hemoglobin (HbA1c), blood lipids, insulin, inflammatory markers, medication use, depression, quality of life, and physical activity will be conducted at baseline and at 6-, and 12-months after randomization. A 3-month post-intensive intervention assessment will measure short-term changes in body weight, diet, and metabolic syndrome indicators.

Inclusion Criteria:

1. Meet diagnostic criteria for the metabolic syndrome;
2. Interested in losing weight and have a BMI 30-40.22 BMI>40 kg/m2 indicates severe obesity and is associated with functional limitations that are likely to prevent participation in the study;
3. Age 21 to 70 years old;
4. Telephone in the home or easy access to one;
5. Can provide informed consent;
6. Physician's approval to participate in the study;
7. Non-smoking status (given nicotine's effect on weight suppression, on HDL, and smoking cessation's effect weight gain); and
8. Ability to speak and read English.

Exclusion Criteria:

1. Has clinically diagnosed diabetes, or a fasting blood sugar of ≥ 126 mg/dl;
2. Had an acute coronary events within the previous 6 months;
3. Pregnant or lactating;
4. Women with polycystic ovary syndrome;133
5. Plans to move out of the area within the 12-month study period;
6. Diagnosis of a medical condition that precludes adherence to study dietary recommendations (e.g., Crohn's disease, ulcerative colitis, active diverticulitis, renal disease);
7. Has major depression or suicidality;
8. Is following a low-carbohydrate, high-fat dietary regimen such as the Atkins' Diet.134 Is participating in any current weight loss program;
9. Has had bariatric surgery or is currently using weight loss medication; and
10. Has an eating disorder (anorexia nervosa, bulimia nervosa or binge eating). Patients on lipid-lowering medications will not be excluded, but should be on a stable dose for 6 months.