Weight loss seems simple

A calorie is a calorie, the advice goes. Eat too many ... gain weight. Eat fewer ... lose weight. But many believe weight loss is more than a calorie equation, with so-called new-and-improved ways to lose weight being ever popular. Americans spend an estimated $42 billion annually on weight loss foods, products, and services. With that much money at stake, it's no surprise there are an overwhelming number of "fad" diets and other weight-loss products on the market.
Having so many diet options makes it difficult to know which ones to trust. For this reason, The Partnership for Healthy Weight Management has developed the "Voluntary Guidelines for Providers of Weight Loss Products or Services." The mission for these guidelines is to "promote sound guidance to the general public on strategies for achieving and maintaining a healthy weight." According to the guidelines, effective weight management involves:
Behavior modification that includes:

• Dietary intervention
• Healthful eating in accordance with the Dietary Guidelines for Americans
• A reduction in calories
• A lowered fat consumption
• An increase in fruit, vegetable, and whole grain consumption
• Physical activity
• Increased frequency
• At least moderate intensity

Medical, pharmacological, and surgical intervention:

• May be necessary for people with more serious cases of overweight and obesity
• Have to be used in conjunction with behavior, diet, and physical activity modifications

Read more about these guidelines at www.consumer.gov/weightloss/guidelines.
It is important to look for a plan that includes strategies for maintaining weight loss. There is nothing worse than regaining the weight that took you an enormous amount of hard work and patience to lose.
Most popular diets are considered fad diets. There is no clear definition for what constitutes a fad diet. Merriam-Webster defines a fad as "a practice or interest followed for a time with exaggerated zeal." Fad diets often promise quick results with a short time commitment. Long-term success requires permanent changes in behavior, diet, and activity.
Ways to spot a fad diet:

• It claims fast weight loss
• Claims that sound too good to be true
• Foods defined as "good" and "bad"
• Less than 1,000 calories daily
• A required vitamin/mineral supplement or food product
• Elimination of a major food group (grains, fats, meats, dairy, fruit, vegetables)
• Lack of long-term randomized scientific studies proving the diet works and is safe. A randomized study distributes participants in a deliberately random way into either the non-tested diet group or the special diet group. Some fad diets state there is research to support their claims, but the research is only done with a few people or does not exist.
• Elimination of an essential nutrient (carbohydrates, fats, proteins)
• No activity or exercise needed
• It's written by someone with no expertise in weight management

The following review examines the advantages and disadvantages of several popular diet plans. Many of the diets emphasize the restriction of one nutrient as the basis for their plan. The other food groups and nutrients are allowed in limited or unlimited quantities, depending on the plan. Weight loss is impossible without a calorie restriction, so each diet has to provide fewer calories than your body needs to maintain your weight. Any diet that claims otherwise can end up causing weight gain. Various diet plans are summarized below to help you learn to review them for safety and effectiveness.