Does Slim Fast Work?

Slim Fast shake

Slim Fast is a popular weight loss program that acts as a meal replacement system. It is difficult to gauge the efficacy of such a program as the results can be highly individualized and dependent on numerous factors. In theory, diets that restrict calories and provide adequate nutrition should result in weight loss. The National Institute of Health (NIH) has been reporting for years regarding reduced calorie diets and their ability to result in weight loss. Through effective meal replacement strategies, Slim Fast consumers should be able to lose a certain amount of weight over time. How dramatic or rapid the results will be, however, varies from person to person.

Slim Fast Meal Replacements

The Slim Fast "plan," as illustrated on the company website, consists of several varieties of snack bars, shakes, meal replacement bars, and 500 calorie entrees. In reference to the NIH's recommendations for safe weight loss, you'll note one pound of fat is the equivalent of 3,500 calories. Hence, the average individual must restrict his weekly intake of food by 3,500 calories in order to lose one pound of fat in seven days.

How Slim Fast Makes it Easy

Each of Slim Fast's snack bars, shakes, meal replacement bars and entrees has a specific calorie count. You can easily cut your calories by following the Slim Fast recommendations and replacing both breakfast and lunch with a shake or a meal replacement bar. By consuming only one entrée for dinner, you calorie reduction for the week can be quite substantial.

Determining Factors

Several other factors can undermine or enhance weight loss, despite adherence to Slim Fast products. Amongst these may be:

  • Health conditions that may affect metabolism
  • Current exercise regimen
  • Food allergies
  • Your dedication to safe weight loss

Your Underlying Health

Calorie reduced diets follow textbook suggestions for weight loss; however, many medical conditions can affect your metabolism. Conditions such as an under active thyroid or a blood sugar disorder may slow down your metabolic rate, regardless of your best calorie-cutting efforts. Many Slim Fast items contain high amounts of sugars and carbohydrates which are not recommended for specific health issues. This is why it is always important to consult a physician before attempting any dietary changes.


Many health resources, including the Mayo Clinic, highlight the importance of a joint diet and exercise plan for safe and effective weight loss. Slim Fast products are processed foods and cannot be fully comparable to the life-promoting properties of many fresh dairy, produce, and meat items. However, many healthy foods are also high calorie. Depending solely on Slim Fast foods is not an entirely healthful approach, as your diet will consist entirely of water and processed foods.

By enhancing your Slim Fast regimen with exercise, you can cut and burn calories without having to exclude certain whole and healthy foods from your diet.

Food Allergies

A study outlined by merely states what many researchers are now confirming: food allergies can affect your metabolism. Regardless of a calorie reduced diet, if you are allergic to any of the foods contained within Slim Fast products, your weight loss can be affected.

Losing Weight Safely

You can theoretically lose several pounds a week by drastically reducing your caloric intake. However, such an approach is hardly healthy. The NIH has listed the lowest recommended caloric for dieters as:

  • 1,200 for women
  • 1,500 for men

Going below such a limit may result in metabolic disturbances and even severe health problems over time.

Key Findings and Conclusions

For dieters keeping the above considerations in mind, it can be very possible for the Slim Fast program to induce weight loss. Research provided by Vanderbilt University has confirmed that careful Slim Fast dieters do lose weight effectively, averaging a loss of about 1 to 2 pounds a week. Many dieters were able to keep this weight off long term; however, they were educated regarded a calorie counting approach and did not divaricate from such a regimen.

Again, dieters should consult a medical professional before attempting a Slim Fast diet to rule out any medical factors that would deem the Slim Fast approach unsafe for a particular individual.

Does Slim Fast Work?