At least one-third of the people in Westernized countries are overweight. Losing weight—and keeping it off—is a constant struggle for millions of people. Many experts are now saying that weight control consists of four components: strength training (to build lean muscle), cardiovascular training (to increase the metabolic rate), proper nutrition (to feed the body, but manage the calories), and mental toughness (to begin and stick with a program). For many, proper nutrition includes some of the following supplements.