Health Benefits of Weight Loss
Several studies have shown that the major benefit of weight loss is that it improves not merely one risk factor but the entire risk-factor profile. Health benefits increase as weight loss moves along a scale from modest to substantial, but modest weight loss nonetheless produces clinically significant benefits. Accordingly, modest weight loss is appropriate initial therapy for obese patients with comorbid conditions. Maintaining a modest weight loss, moreover, is more desirable than achieving a larger weight loss that will be regained. For example, a man who decreases his BMI from 40 kg/m2 to 38 kg/m2 (~5% weight loss) will theoretically decrease his mortality risk by 12%.
Weight loss of 10% or less can improve the complications most commonly associated with obesity. This amount of weight reduction has been shown to improve glycemic control in obese patients with type 2 diabetes, reduce blood pressure in obese patients with hypertension, and improve lipid levels in obese patients with dyslipidemia.
The health benefits of weight loss in patients with type II diabetes have been studied extensively. One such study, comprising 263 patients with type II diabetes or impaired glucose tolerance, correlated each average 1-kg (2.2-pound) weight loss with a 3-4 month survival increase. A 10-kg weight loss would restore the 35% loss of life expectancy associated with the diagnosis.
A 1-year study of 114 obese patients with type II diabetes assessed the long-term effects of modest weight loss. Treated with a three-pronged program of diet, exercise, and behavioral therapy, participants who lost 5%-10% of their body weight saw significant improvement in HbA1c levels. Weight loss of 6.9-13.6 kg also improved fasting blood glucose, insulin, triglyceride, and HDL cholesterol values. Although early effects of the weight loss were greater than those seen at 1 year, improvement in HbA1c was still evident, suggesting that modest weight loss can maintain better control.
Hypertension is more likely to accompany obesity than normal weight, and weight loss appears to lower blood pressure as an independent effect. Although substantial (>10%) weight loss is unequivocally associated with lowered blood pressure, the effect is frequently reported with modest weight loss. Reducing weight in the patient with hypertension lessens obesity-associated increases in cardiac output, blood volume, and intracellular sodium. Benefits directly relate to the amount of weight lost. A 12-kg loss lowers blood pressure an average 21/13 mm Hg, even in patients with untreated hypertension.
Metabolic improvement often exceeds predictions based on the amount of weight lost. Why does losing small amounts of weight have so powerful an effect on risk factors? The seemingly disproportionate health dividends of a 5%-10% weight loss have been attributed to a predominant reduction in visceral fat -- as much as 30% of visceral fat. Loss of atherogenic and diabetogenic visceral fat improves the metabolic profile as a whole, regardless of the ideal body weight.
Prog Cardiovasc Nurs. 2001;16(3) © 2001 Le Jacq Communications, Inc.
© 2007 Prog Cardiovasc Nurs
Cite this: Treating Obesity: A New Target for Prevention of Coronary Heart Disease - Medscape - Jul 01, 2001.