Meal replacements are dietary supplements designed to substitute for a complete meal in your diet plan. Popular in weight loss regimens, complete meal replacements often contain high levels of dietary protein, along with vitamins, minerals, some carbs and very little fat. While these supplements may assist in shedding pounds, consult with your health care provider before beginning any new weight loss routine.
Background
The rationale behind meal replacements rests with knowing exactly how many calories each meal replacement contains. It is often difficult to calculate the number of calories in a whole-food meal, making it challenging to accurately assess your daily calorie intake. Meal replacements offer exact calorie counts, allowing you to determine and track your daily calorie goals. In addition, diets rich in protein improve your satiety, or feeling of fullness, states Dr. Leo Treyzon in the Aug. 27, 2008, volume of "Nutrition Journal." This feeling may lead you to consume fewer total calories throughout the day when using a high-protein meal replacement supplement, helping you lose weight.
Types
Complete meal replacements may take the form of shakes or nutrition bars. The protein in these meal replacements often derives from whey, a type of milk protein, or soy, a nutritionally complete plant protein. Protein shakes are available premixed and ready to consume or as a powder to be mixed with water, milk or juice. If you mix meal replacement powder with milk or juice, include those extra calories as part of your daily allotment.
Benefits
Including high-protein meal replacements in your weight-loss diet may help you lose weight. Dr. Monica Zangwill of the University of Southern California Norris Cancer Hospital reports that study subjects who consumed meal replacements had a greater rate of weight loss compared with those on a food-based diet. Convenience and the ease of calorie counting are other benefits of including meal replacements as part of your weight loss program. The high protein content of these supplements adds to their advantage. A protein-rich diet not only increases your satiety but also helps preserve your lean body mass, so the weight you lose is more fat tissue and less muscle tissue.
Risks
While convenient, high-protein meal replacements do not teach you to make sensible and healthy food choices as a lifestyle change. Without this, you may revert to your old food habits once you stop supplementing with meal replacements, possibly gaining back the weight you lost. Meal replacements may not be suitable for long-term use because they may lack one or more essential nutrients. In addition, some high-protein shakes may be contaminated with heavy metals, according to the July 2010 issue of "Consumer Reports."
Considerations
As with other dietary supplements, meal replacements do not fall under regulation by the U.S. Food and Drug Administration. Therefore, meal replacement labels may be inaccurate, possibly compromising your health. Also, your body may not react well to specific ingredients in your meal replacement. For example, you may be allergic to soy or whey proteins, and should avoid meal replacements containing these ingredients.
References
- University of Southern California Norris Cancer Hospital: Diet Shakes and Meal Replacements: Can They Really Help You Lose Weight?
- PubMed Central: A Controlled Trial of Protein Enrichment of Meal Replacements for Weight Reduction With Retention of Lean Body Mass
- University of Illinois McKinley Health Center: Creatine and Whey Protein Supplements
- Cambridge Health Alliance: Consumer Reports Investigates: Alert: Protein Drinks
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