Beef in an Optimal Lean Diet (BOLD) Effects on Metabolic Syndrome

BOLD (Beef in an Optimal Lean Diet) Effects on Established and Emerging Cardiovascular Disease (CVD) Risk Factors: Effects on Metabolic Syndrome (BOLD-X)

The proposed research will provide important information about the role of 2 intervention diets that provide different amounts of lean beef and meet current nutrient recommendations for the treatment of Metabolic Syndrome (MetSyn), a chronic disease that is still increasing in prevalence at alarming rates. The experimental and diet designs will enable us to evaluate lifestyle interventions for MetSyn for persons who maintain weight, lose weight and maintain their weight loss, as is currently recommended in clinical practice. Importantly, the investigators will compare a diet high in lean beef (5 oz/day) which is compositionally similar (i.e., energy and nutrients) to the modified-DASH diet, a low beef diet which has become the Gold Standard for the management of cardiovascular disease (CVD) risk factors, including MetSyn. In addition, the investigators also will evaluate a moderate-high protein diet (BOLD+) that is higher in total protein (from mixed sources including lean beef, 7oz/day) than the BOLD diet, on CVD risk factors in persons with MetSyn. A follow-up study was conducted to assess dietary compliance in a sub-sample of the population at 12-months; participants were not informed of this end-point and additional consent was obtained.

Hypotheses:

1. Healthful isocaloric diets that include lean beef as the primary source of protein (BOLD diet) with average (18%; BOLD) or moderate-high (28%; BOLD+) total protein intake will show similar or greater reductions in CVD risk, respectively when compared to a modified-DASH diet.
2. A healthful weight-loss diet, including lean beef as the primary source of protein in a high-moderate protein diet (BOLD+ diet), plus regular exercise (BOLD+ + ex) will reduce body weight equal to that of a BOLD + ex and DASH + ex intervention, but may improve CV risk factors (such as BP and TG), and therefore reduce the prevalence of MetSyn more than a BOLD + ex and DASH + ex intervention.
3. The BOLD diet will be more effective than the modified-DASH diet, and the BOLD+ diet more effective than the BOLD diet in maintaining the CVD benefits attained during phases 1 and 2. Dietary adherence will be better on the BOLD and BOLD + diets compared with the modified DASH diet.

Inclusion Criteria:

• (BMI 27-42 kg/m2)

• Three or more of the following risk factors (defined as having MetSyn):

  • abdominal obesity [waist circumference > 102 cm (40 inches) in men and > 88 cm (35 inches) in women],

  • elevated blood glucose [> 110mg/dl (6.1 mmol/L)]

  • elevated TG [>150 mg/dl (1.7 mmol/L)]

  • low HDL-C [<40 mg/dl (1.03 mmol/L) in men and <50 mg/dL (1.29 mmol/l) in women]

  • hypertension (Systolic Blood Pressure > 130 mmHg or Diastolic Blood Pressure > 85 mmHg)*

    • BP medication accepted if BP stable and less than 160/100mm Hg

Exclusion Criteria:

• A history of myocardial infarction, stroke, diabetes mellitus, liver disease, kidney disease, and thyroid disease (unless controlled on medication)
• Lactation, pregnancy, or desire to become pregnant during the study
• Intake of putative cholesterol-lowering supplements (psyllium, fish oil capsules, soy lecithin, niacin, fiber, flax, and phytoestrogens, stanol/sterol supplemented foods)
• High alcohol consumption (≥ 14 drinks/week)
• Participation in regular physical activity (> 1 formal session/week)
• Lipid or glucose lowering medication