3.3.0.0 Lifestyle Interventions
Significant weight loss can be attained with lifestyle programs that achieve a 500–750 kcal/day energy deficit, which in most cases is approximately 1,200– 1,500 kcal/day for women and 1,500– 1,800 kcal/day for men, adjusted for the individual’s baseline body weight. Weight loss of 3–5% is the minimum necessary for any clinical benefit (21,30). However, weight-loss benefits are progressive; more intensive weight-loss goals (>5%, >7%, >15%, etc.) may be pursued if needed to achieve a healthy weight and if they can be feasibly and safely attained.
These diets may differ in the types of foods they restrict (such as high-fat or high-carbohydrate foods) but are effective if they create the necessary energy deficit (21,31–33). Use of meal replacement plans prescribed by trained practitioners, with close patient monitoring, can be beneficial. Within the intensive lifestyle intervention group of the Look AHEAD trial, for example, use of a partial meal replacement plan was associated with improvements in diet quality (34). The diet choice should be based on the patient’s health status and preferences.
Intensive behavioral lifestyle interventions should include ≥16 sessions in 6 months and focus on diet, physical activity, and behavioral strategies to achieve an ˜500–750 kcal/day energy deficit. Interventions should be provided by trained interventionists in either individual or group sessions (30).
Patients with type 2 diabetes who are overweight or obese and have lost weight during the 6-month intensive behavioral lifestyle intervention should be enrolled in long-term (≥1 year) comprehensive weight-loss maintenance programs that provide at least monthly contact with a trained interventionist and focus on ongoing monitoring of body weight (weekly or more frequently) and/or other self-monitoring strategies such as tracking intake, steps, etc.; continued consumption of a reduced-calorie diet; and participation in high levels of physical activity (200–300 min/ week (35). Some commercial and proprietary weight-loss programs have shown promising weight-loss results (36).
When provided by trained practitioners in medical care settings with close medical monitoring, short-term (3-month) interventions that use very low-calorie diets (defined as ≤800 kcal/day) and total meal replacements may achieve greater short-term weight loss (10%–15%) than intensive behavioral lifestyle interventions that typically achieve 5% weight loss. However, weight regain following the cessation of very low-calorie diets is greater than following intensive behavioral lifestyle interventions unless a long-term comprehensive weight-loss maintenance program is provided (37,38).