Cons of Take Shape for Life

Medifast's Take Shape for Life is a very low calorie, liquid meal replacement diet program. Initially, dieters are permitted five meals per day of Medifast's soy- and whey-based shakes, pudding, oatmeal, and other food substitutes, as well as one conventional meal, though this is severely restricted to low calorie, healthy components such as 5-7 ounces of fish or lean meat, vegetables and salad. After this 800-1,000 calories per day period of weight loss, the restrictions taper off gradually to a level appropriate for long-term maintenance. In addition to the substitute food products, the Take Shape for Life program includes exercise guides, advice from dieticians and personal trainers, an online community, and other support services.

Health Risks of Rapid Weight Loss

• Any diet allowing so few calories per day is a crash diet, and crash diets carry certain inherent risks. They can lead to low blood sugar, low blood pressure, ketoacidosis (dangerously high levels of acidic ketones in the blood), weakness and dizziness. Because they tend to result in greater weight loss over a shorter period of time, they leave dieters prone to the "yo-yo diet" phenomenon, where the body lowers its metabolism to stave off starvation, and then adds the weight back when the diet is discontinued.

  A crash diet should only be undertaken under the supervision of a physician. Take Shape for Life is based on a diet designed by a Johns Hopkins physician for obese patients facing surgery and needing to reduce their weight significantly in a short time period, but that doesn't mean it's safe; it means it's safer than undergoing certain forms of surgery at certain levels of obesity.

Difficulty of Sticking to the Initial Diet

• Medifast has designed its food substitutes to be more filling than would typically be the case for something of so few calories. That helps, but only to a limited degree. Expect to be hungry, indeed very hungry, during that initial 800-1,000 calories per day period. You'll be eating a lot less than you're used to, and you'll likely be eating little or none of most of your favorite foods. An allowable "snack" is a stalk of celery, a sugar-free popsicle or a diet soda. No beer, bread, candy, fruit or fruit juice, cheese and so on.

Difficulty of Maintaining the Weight Loss

• Certainly the Take Shape for Life plan becomes gradually less onerous as you transition to the maintenance phase. However, you still have to practice considerable self-discipline in how you eat, and it isn't just about eating; the plan also calls for exercising five days a week to keep the weight off.

  This is not a criticism of Take Shape for Life per se, as it applies to diets in general. Healthy and sustained weight loss requires significant---and for most people, difficult---permanent lifestyle changes. There's nothing magic about Take Shape for Life that changes this reality.

Cost

• Expect to pay about $300 per month for the food substitutes you'll need for the Take Shape for Life diet. If you weren't on the diet, you'd still have to buy food, which might or might not be $300 per month. If you take into account what you normally spend for food and factor that into the plan's cost, it may or may not be financially feasible for you.