However, the term supplements refers to foods intended to supplement the normal diet, not to replace it. Meal replacements are meant to be more filling and contain more calories than a protein supplement. Although meal replacements have more calories than protein supplements, they tend to be lower in calories than a real meal, which can help you lose weight. Meal replacements may contain only 10 grams of protein per serving (for general health), while some meal replacements may contain higher amounts of protein (especially those used for weight loss programs, since proteins help you feel satisfied and help maintain lean body mass during weight loss).
A meal replacement shake is usually a protein-based drink with a multivitamin component. Meal replacement shakes don't usually contain fruits, vegetables, or grains, but they're usually rich in the nutrients found in those foods. For more information about when a protein supplement or meal replacement might be right for you, talk to your healthcare provider. Meal replacements typically provide 200 to 250 calories per serving (although some can reach 400 calories per serving) and are fortified with more than 20 vitamins and minerals (at a good or excellent source level), healthy carbohydrates (including fiber) and healthy fats.
Protein supplements typically provide 100 to 120 calories per serving, and protein amounts vary by brand (many protein supplements contain approximately 20 grams of protein per serving). A protein shake, on the other hand, is primarily intended to provide protein and is generally designed to add protein to the diet, not to replace a meal. You shouldn't rely solely on meal replacements for an extended period of time without consulting your doctor, due to the decrease in your intake of “real foods”, such as fruits and vegetables. Protein products and meal replacements differ in their nutritional composition and are designed for different purposes.
The meal replacement category has changed dramatically as consumers began to more actively incorporate nutritional supplements, such as proteins, into their daily diets. A whole-food diet that uses supplements to fill in the gaps is the best way to live a healthier life, have the most energy and lose weight sustainably. As ready-to-eat or easy-to-prepare foods, meal replacements can come in a variety of forms, such as food bars, shakes, and powders that can be mixed with milk. While someone might choose to replace a meal with a protein shake, if that shake isn't rich in vitamins and minerals, it's not an adequate substitute for a meal.
The inclusion of vitamins and minerals provides essential nutrients that are generally found in a food from foodborne foods. Today, meal replacements seem to focus on nutrient density rather than on specific health outcomes.