Although no single dietary approach has been found to have a metabolic advantage or be most likely to support long-term weight maintenance,15,25-28 energy balance is central. It is critical to induce a negative energy balance—with a deficit of 250 to 500 calories per day to achieve a weight loss of 0.5 to 2 lb per week.
Which diet is best?
Diets emphasizing varying contents of carbohydrate, fat, and protein have generally been found to be equally successful in promoting clinically meaningful weight loss and maintenance over the course of 2 years, although some studies have found specific approaches to encourage initial weight loss.26 Because different strategies have proven helpful to various patients, your best bet is to analyze the patient’s eating pattern and prescribe the diet he or she is most likely to adhere to for at least 6 months.
If the patient has comorbidities, choose the diet expected to have the greatest impact—a low-glycemic diet for an obese patient with diabetes, for example, and the Dietary Approaches to Stop Hypertension (DASH) food plan for a patient with hypertension.27 For premenopausal women, diets low in carbohydrates have been found to facilitate weight loss without negative health consequences.25
Offer specific—and actionable—strategies
Most clinically obese patients (63%, according to 1 study) do not receive weight loss counseling from their primary care physician. Often, they are told to lose weight, but not given advice on how to do so. Providing specific strategies can help patients stay motivated.
One set of specific weight-loss messages comes from the Centers for Disease Control and Prevention (CDC)’s Research to Practice Series.29 Patients are advised to:
- limit eating away from home
- select healthy options when eating out
- eat more fruits and vegetables
- avoid large portion sizes
- eat low energy-dense foods (ie, foods that are high in micronutrients but low in calories per gram).
The CDC also encourages new moms to breastfeed. In addition to helping the women themselves control their weight, breastfed infants appear to be more likely to maintain a normal body weight—an important consideration as overweight children are more likely than children of normal weight to become overweight adults.30 (To learn more about pediatric obesity, see “How best to help kids lose weight”.)
The “5-3-2-1-almost none” plan offers additional advice. Every day, patients should:
- Eat ≥5 servings of fruits and vegetables
- Have 3 structured meals (including breakfast)
- Limit TV/video game use to ≤2 hours
- Engage in ≥1 hour of moderate to vigorous physical activity
- Limit sugar-sweetened drinks to almost none.31
Encourage patients to keep a diary. Suggesting that patients track their food and beverage intake, as well as their physical activity, is another helpful strategy, as self-monitoring creates a sense of accountability and awareness. Patients are likely to need ongoing encouragement to do so, however, because record keeping typically declines with time.32,33
Prescribe physical activity, and sleep
Physical activity guidelines vary for active adults, older adults, and those with disabilities. To attain health benefits, however, the general recommendation is for ≥150 minutes of moderate-intensity physical activity per week, plus muscle strengthening activities at least twice a week.33,34 Help patients identify strategies that will improve adherence, such as wearing a pedometer to gauge miles walked per day or working out with a buddy.34
Sleep duration, too, may affect weight. Although there is insufficient evidence to support the idea that sleep is an independent risk factor for obesity,35 it appears that those who sleep too much (9-10 hours per night) or too little (5-6 hours) have a 3- to 5-lb weight gain compared with those who sleep for 8 hours. One possible explanation is that there is a disruption in the production of hormones that affects appetite.4 Advise patients that getting enough sleep can help them control their weight.
Consider meal replacement, pharmacotherapy
For select patients, adherence to a low-calorie diet can be facilitated by the use of meal replacement products, as well as by pharmacotherapy. Each approach yields about a 5% to 7% weight loss.36 High-protein, high-fiber calorie-controlled shakes or bars can be particularly helpful for patients who have difficulty with food selection or portion control and can be effectively monitored by a physician or dietitian.37,38 Dietary fiber is also helpful in decreasing food intake and hunger.