By Barbara Broggelwirth, RDN, CDN

Meal replacement shakes have become very popular for promoting weight loss, but how do you know if they are safe and effective for you? Registered Dietitian Nutritionists (RDN’s) are the perfect resource to pose this question to because they assess the whole individual before making a blanket decision. Since everyone doesn’t always have access to an RDN, I hope these guidelines will help you navigate what works best for you.

When considering meal replacement options, a few questions come immediately to mind. For instance, do you have any other health conditions that might put you at risk? Do you have diabetes and need to limit your total carbohydrates added sugars? Do you have any conditions that requires a fluid restriction such as chronic kidney disease or congestive heart failure? Are you lactose intolerant? Do you have any food allergies? Do you avoid animal proteins and follow a vegetarian or vegan diet? And last, is the intention to use the shakes as meal replacement for all meals or just one meal per day?

Meal replacements are defined as any food that’s consumed as a substitute for a meal or part of a meal. They provide a prepackaged amount of energy and nutrients, although these vary greatly among products. The advantage of consuming shakes as a meal replacement, is that it offers individuals a pre-measured amount of nourishment with specific calorie, protein, and nutrient levels. This eliminates the need to weigh, measure, or estimate portion sizes. There products are sold as powders, to be mixed with water or other liquid, or ready-to-drink containers.

The term “meal replacement” is not defined by the Food and Drug Administration (FDA), but in order to meet an individual’s nutrient needs it is important to choose supplements that include all of the “essential” nutrients. An “essential nutrient” is a compound that your body can’t produce on its own and is needed for health and everyday functions. There are six classes of essential nutrients: water, carbohydrates, proteins (essential amino acids), fats (essential fatty acids), vitamins and minerals.

Once you have determined what your health and wellness goals are, you can begin to consider a meal replacement plan. You can replace one meal (a breakfast on the go) or use as a sole source of nutrition, consumed three or more times per day. While most meal supplements provide about 150 to 200 kcal, some may contain more than 400 kcal each.

Choosing the product that fits your needs:

  1. Lose weight — To lose weight, choose products with no added sugars or dextrins/maltodextrins (sweeteners made from starch). Don’t select those with added branched-chain amino acids (BCAAs), as they help promote muscle growth and weight gain.
  2. Vegetarian or Vegan — If you are a vegan or a vegetarian who avoids dairy, don’t choose milk-based protein shakes (e.g., whey, casein or milk proteins); instead choose 100 percent plant proteins (e.g. pea, soy, hemp, rice).
  3. Diabetes — Patients who have diabetes should choose protein shakes low in sugar (less than 5 grams) and total carbohydrates (e.g. don’t choose products with sugar listed as one of the first three ingredients).

Research supports that liquid meal replacements can be a safe and effective way to lose weight in the short term, but without a long-term strategy to reintroduce whole foods, it is easy to fall back into old habits and regain weight. Weight loss maintenance strategies such as food shopping and meal prepping can seem burdensome to someone who is new to adopting these habits and they may find them unsustainable. Therefore, weight loss programs that recommend meal replacements are only effective if they include education to help individuals transition into a lifestyle that supports health and weight loss long term. Remember, it is always a good idea to consult your doctor before starting any new meal replacement plan.


  1. Heymsfield SB, van Mierlo CA, van der Knaap HC, Heo M, Frier HI. Weight management using a meal replacement strategy: meta and pooling analysis from six studies. Int J Obes Relat Metab Disord. 2003;27(5):537-549
  2. 7 Tips for Choosing the Best Protein Powder for You. Health Essentials from Cleveland Clinic. Published 2019. Accessed March 28, 2019.


Barbara Broggelwirth is a Registered Dietitian Nutritionist who is currently working with Bariatric and Medical Weight Management patients.  She works with patients to help them achieve their health and weight loss goals.