This is an excerpt from Fitness Professional's Handbook 7th Edition With Web Resource by Edward Howley & Dixie Thompson.
Although each individual must assess which areas of her lifestyle contribute to excessive weight accumulation, common steps that benefit the majority of people who are attempting to lose weight include the following:
- Reduce total calories.
- Reduce fat and carbohydrate (particularly simple sugar) intake.
- Increase physical activity.
- Adopt healthy eating behaviors.
As previously mentioned, a negative caloric balance must be established for weight loss. The number of calories consumed while attempting to lose weight should be determined by the client’s health, caloric need, and ultimate weight-loss goals. Most healthy adults who need to lose weight can institute a short-term low-calorie diet (LCD) consisting of 800 to 1,500 kcal · day-1 without major adverse consequences. Very-low-calorie diets (VLCDs) consisting of -1 are sometimes used in specialized settings to treat individuals with extreme obesity (22). In these cases, physicians and dietitians provide patient oversight (22). VLCDs can lead to substantial weight loss, and years of study with this approach have yielded carefully monitored protocols with few negative side effects (42).
ACSM recommends that weekly weight-loss goals should target a loss of 1 to 2 lb or 0.5 to 0.9 kg (1). A general guideline is to establish a caloric deficit of 3,500 to 7,000 kcal · wk-1 (500-1,000 kcal · day-1), which theoretically results in a 1 to 2 lb loss (0.5 to 0.9 kg) of fat each week (1 lb of fat = 3,500 kcal). ACSM also recommends that people restricting their caloric intake limit their fat intake to less than 30% of total calories (1). These are general recommendations, and people with special needs (e.g., athletes, older adults, people with metabolic disorders) may require a different approach to weight loss. Caloric restriction can lead to decreased RMR and fat-free mass. The decrease in RMR and loss of fat-free mass will be greater in dieters with large daily caloric deficits (34).
Exercise prescription for weight management and weight loss
ACSM recommends a combined approach of exercise and moderate caloric restriction for people attempting weight loss (1, 2). Although debate continues over the precise contribution of exercise to weight management, a combination of exercise and moderate calorie restriction appears to be most effective in maintaining lean mass and avoiding excessive decreases in RMR. Existing data clearly demonstrate that people who are successful in maintaining weight loss engage in regular aerobic activity (47). Studies also show that regular exercise helps prevent weight gain (10, 17, 21). From a theoretical perspective, adding exercise to everyday life can significantly alter body weight. For example, expending just 100 kcal · day-1 beyond daily caloric need for a year creates a caloric deficit of 36,500 kcal. ACSM recommends that individuals engage in a minimum of 150 min of moderate-intensity exercise per wk and further states that additional exercise (200-300 min per wk) is more likely to be associated with successful weight control (1, 2). The following are specific recommendations for weight management and weight loss with exercise (1):
- Frequency: ≥5 days per wk.
- Intensity: Begin with moderate intensity (40%-60% HRR), eventually progressing to higher intensity (≥60% HRR).
- Time: Begin with short, easily tolerated bouts preferably totaling 30 min per day. Progress to 60 min per day. Multiple daily bouts can be used with bout duration of 10 min or longer.
- Type: Aerobic exercise targeting large muscle groups. Resistance and flexibility exercise is recommended as a supplement to aerobic activity.
In addition to the physical benefits, psychological variables improve with exercise. Improvements in self-esteem and self-efficacy are commonly reported outcomes of regular exercise. The empowerment that comes from becoming more fit can add to the resolve to live a healthy lifestyle and maintain a healthy weight.
Learn more about Fitness Professional’s Handbook, Seventh Edition With Web Resource.