SlimFast & Weight Loss

Slim-Fast is one type of meal replacement diet. According to the MayoClinic, meal replacement diets involve buying a prepackaged drink or bar and eating that instead of a regular meal. Over the short term, you can lose a modest amount of weight on a meal replacement plan. The difficulty is in the long-term; meal replacements can get boring after six months or so, and the weight will come back if you return to your old eating habits.

How it Works

According to the Slim-Fast website, the plan includes three healthy 100-calorie snacks, two meal replacement bars or shakes, and one 500-calorie meal. The shakes average 200 calories each. That adds up to a grand total of 1,200 calories per day. The American Heart Association recommends that a moderately active female from 31 to 50 years of age should consume 2,000 calories per day to maintain a healthy weight; the difference produces a calorie deficit leading to weight loss.

Results

The Slim-Fast website claims you should lose about 1 to 2 lbs. per week on the plan, which is a safe and moderate weight loss. A 2006 BBC study by Helen Truby and others supports that assertion. In the BBC report, participants on the Slim-Fast plan lost 6.8 percent of body weight and 5.3 percent of body fat during six months.

Nutrition

Slim-Fast was designed for the purpose of weight loss, so it is nutritionally streamlined. One serving of Chocolate Royale shake mix has 4 g of fat, 30 g of carbohydrates and 10 g of protein. In addition to these energy-providers, the shakes also have dietary fiber and a range of vitamins and minerals. A study published in 2007 in "Nutrition Journal" by Judith Ashley and others showed that women following a Slim-Fast plan had more adequate essential nutrient intake than women on a traditional food-group diet.

Challenges

As with any diet plan, the hard part is doing it. You have to make up your mind that you are willing to replace meals with shakes and bars, and that your added snacks meets the plan's guidelines. Prepared Slim-Fast foods save time on cooking, but at a cost. Depending on whether you choose shake mix, canned shakes or bars, the plan can cost $10 or more each day. If you like fresh foods, variety and eating out, this diet may be difficult for you.

Adherence

In the BBC study, only 21 percent of the original participants were still using the Slim-Fast plan at the end of six months. Participation dropped more dramatically at one year. Aside from the challenges mentioned above, another long-term adherence problem may be that Slim-Fast is a go-it-alone solution. The company offers an online support group, but there are no face-to-face meetings in this plan, and accountability is entirely up to you.