Labdoor analyzed 15 of the best-selling meal replacements in the United States for macronutrients (e.g. calories, protein, fats, fiber), vitamins and minerals, and toxic heavy metal (arsenic, cadmium, lead, mercury) contamination.
Overall, products in this batch performed well in label accuracy for macronutrients; measured calories deviated from label claims by an average of 8%. Products on average measured 19.4 g of protein per serving, ranging from 2 g/serving to 41 g/serving, and 4.8 g of fat per serving, ranging from 1 g/serving to 21 g/serving. Products were scored on nutritional value and how well they keep you full so you don't overeat later. Research suggests that consuming 25% of calories from protein2, adequate fiber content3, and foods with low glycemic loads4 are best for maintaining fullness. 10 of 15 products failed heavy metal screenings for lead1. Vega One Nutritional Shake and MET-Rx Original Meal Replacement failed screenings for both lead and cadmium. Artificial sweeteners were also common, notably sucralose, acesulfame potassium, and aspartame5.
On average, products measured 7% more calories than they claimed.
Products generally performed well in terms of label accuracy for macronutrients. About two-thirds of all products measured total calories within 10% of their label claims, and all but 1 product measured protein levels within 5% of their label claims. Sodium levels, however, were off by an average of 44% compared to claims. Vega One Nutritional Shake was most extreme with more than 4 times its label claim for sodium.
On average, products were more inaccurate with claims for vitamins and minerals. Products recorded the largest average deviation for selenium, deviating an average of 412% from claims with an extreme of +3219% recorded by Vega One Nutritional Shake.
Each product's label accuracy score was based on how accurately the product reported active ingredients according to FDA labelling guidelines and standards for rounding.
Only 2 of 15 products were determined to not exceed CA Prop 65 safety limits for lead, arsenic, cadmium, and mercury.
Heavy metal contamination was an issue. 10 of 15 products failed screenings for lead. 2 products failed screenings for both lead and cadmium. A product fails a screening when the amount of a heavy metal in one serving exceeds either the proposed or established limit for how much is safe to consume in a full day as published in California Proposition 651.
All products passed screenings for arsenic.
Total calories in this testing batch ranged from 99 kcal/serving to 413 kcal/serving.
Based on data from federal health organizations6,7,8, breakfast is typically the most nutrient-dense meal of the day, consisting of: at least one-sixth of a day's worth of fiber (4.2 g) and protein (8.3 g) and one-third of a day's worth of vitamins and minerals (FDA recommendations), as well as no more than one-sixth of a day's worth of calories (333 kcal, assuming a 2000 kcal/day diet), fat (7.4 g), sugars (4.2 g), sodium (383 mg), or cholesterol (50 mg). Nutrition measurements for each meal replacement was then compared to these standards.
4 of 15 products achieved scores of at least 9 (out of 10) for satisfying these recommendations for all 3 categories of macronutrients, vitamins, and minerals - IdealShake, GNC Total Lean, MET-Rx Original Meal Replacement, and Vega One Nutritional Shake.
Overall, products measured an average of 198 total calories, 19 g of carbohydrates, 4.8 g of fat, and 20 g of protein per serving. Slimfast Original was a notable outlier with only 2 g of protein per serving. Soylent was an outlier as well, measuring 21 g of fat per serving. Also of note, Boost High Protein measured 10405 IU/serving of vitamin A, crossing the safe upper limit of 10000 IU for the most synthetic vitamin A you should eat in one day.
7 of 15 products recorded sucralose, an artificial sweetener linked to increased cancer risk.
Products were penalized for additives based on the Center for Science in the Public Interest (CSPI)'s safety ratings for additives9. Artificial sweeteners, listed in CSPI's "avoid" category, were an issue in this batch. 7 products had sucralose, 6 products had acesulfame potassium, and 1 product had aspartame. In addition, 5 products claimed artificial flavors, categorized by CSPI as an additive "certain people should avoid" due to risks for "acute, allergic reactions, intolerance, or other problems."
Common allergens in meal replacements include milk sources and soy. Please consult your doctor to confirm your risk for any allergies.
Products in this testing batch measured an average of 19.4 g of protein per serving.
In addition to satisfying nutrient recommendations for a healthy and balanced meal, products were also graded on how well the could keep you full for longer. Research suggests that meals composed of at least 25% of total calories coming from protein help keep you full for a longer period of time, and help you control your eating during the next meal2. On average, products measured 19.4 g of protein, ranging from 2 g/serving in Slimfast Original to 41 g/serving in MET-Rx Original Meal Replacement.
On average, products recorded 5 g of fiber per serving, ranging from 0 g in Boost High Protein to 8 g in GNC Total Lean and Orgain Powder. Research suggests that for keeping you full, foods with at least 5 g of fiber per serving are best3.
On average, products recorded an estimated glycemic load of 3.5; Boost High Protein was highest at 15. Foods with low glycemic loads (10 or less) keep blood sugar levels more consistent, which helps in managing and preventing diabetes, losing weight, and avoiding quick blood sugar spikes and drops 4.
- 1OEHHA. (2016). Proposition 65.
- 2Westerterp-Plantega MS, et al. (2012). Dietary protein - its role in satiety, energetics, weight loss and health. British Journal of Nutrition. 108:S105-S112.
- 3Clark MJ & Slavin J. (2013). The Effect of Fiber on Satiety and Food Intake: A Systematic Review. Journal of the American College of Nutrition. 32(3):200-11.
- 4Anderson GH & Woodend D. (2003). Effect of glycemic carbohydrates on short-term satiety and food intake. Nutrition Review. 61(5 Pt 2):S17-26.
- 5CSPI. (2016).
- 6WHO. (2015). Guideline: Sugars Intake in Adults and Children.
- 7CDC. (2014). What We Eat in America - NHANES 2013-2014.
- 8NIH. (2017). Dietary Supplement Fact Sheets.