How meal replacements may play a role in managing your body weight
Taking a walk down your local grocer’s aisles, you’ll likely be familiar with some of the protein shake products that line the shelves. Thanks to the sudden rise of diet trends in the ’90s, many of these have become a mainstay, along with several new additions over the years. After all, Americans enjoy variety, and they have been socialized to believe that such products are a tool for weight loss.
Indeed, the research shows that meal replacements can be a safe and effective weight control strategy, and their use is associated with long-term success.1 Given that weight regain following weight loss is fairly common, meal replacements are viewed by dieters as an efficient and effective way to manage a reduction in caloric intake and reverse weight gain. But what is it about these products that make them so effective?
First, be advised that although they are often used interchangeably, “meal replacements” and “protein shakes” are not the same and that, like other commercial goods, these are not all created equal. Meal replacements (MR) are generally formulated to contain a certain number of calories per serving (greater than 150) and provide “good” or “excellent” levels of 20+ vitamins and minerals. In essence, they are considered meal replacements because they are nutritionally balanced, contain a certain level of calories, and therefore can replace meals. They may or may not contain fiber but always contain protein, carbohydrate, and some fat, although amounts will vary by product. On the other hand, protein shakes generally contain high amounts of protein but have a more narrow vitamin and mineral profile compared to meal replacements.
In conjunction with other lifestyle behaviors, meal replacement use is cited as a factor in both long-term weight loss and maintenance. You may have heard about very low-calorie diets (VLCD), which are usually recommended to patients before they undergo metabolic and bariatric surgery but may also be utilized by people under medical supervision when the goal is to lose weight rapidly. Limited to 800 calories per day, such individuals consume 4-5 meal replacement products daily for a period of time under the guidance of a physician. Bear in mind that although this is a calorie-restricted diet, individuals will still be able to meet their vitamin and mineral needs through the MR.
Yet another scenario where MRs are practical is during a transition diet phase. In this context, individuals use MRs slightly differently; perhaps they are transitioning off of a VLCD to a low-calorie diet (LCD). In this type of a situation, a person may consume mostly MRs (2-3) with one meal daily. As the transition progresses, and the number of healthy meals increases, the number of MRs consumed drops to one or two daily. This is ideal during maintenance (or as one reaches his or her target weight), given meal replacements’ controlled calorie and nutrient content and ease of adherence.2 No matter the context, MRs are both convenient and effective.
Whether the goal is weight loss, weight management, or weight maintenance, the type of product chosen matters! Protein shakes and meal replacements with excessive calories and an unfavorable macronutrient ratio can be a great way to get offtrack. However, meal replacements that are specifically formulated to deliver an appropriate macronutrient ratio make all the difference. For example, a high-protein, moderate-carbohydrate MR to complement a modified Mediterranean LCD plan; a high-fat, moderate-protein, low-carbohydrate MR for those following a ketogenic LCD plan; or a high-protein formula to support a VLCD plan.
References
- Wadden TA et al. One-Year Weight Losses in the Look AHEAD Study: Factors Associated with Success. Obesity (Silver Spring). 2009;17(4):713–722.
- Soeliman FA et al. Weight loss maintenance: A review on dietary related strategies. J Res Med Sci. 2014;19(3):268–275.
Submitted by Claudia Arroyos
