Protein powders are convenient for boosting protein intake, but they can also lead to consuming more than your body needs. For most healthy adults, surpassing protein requirements usually doesn't cause major problems, but long-term excess may have risks.
Some individuals experience stomach issues from protein powders, particularly those derived from whey or casein. This is common for people with dairy sensitivities, allergies, or lactose intolerance, and can result in gas, bloating, diarrhea, or abdominal cramping. Plant-based proteins (e.g., soy, pea) may also cause bloating due to their high fiber content.
Not all protein powders are low in sugar; some can contain significant amounts, so it's essential to choose products with less than 5 g of sugar per serving to stay within recommended daily limits (24g for women and 36g for men).
Certain protein supplements mixed with high-calorie ingredients can exceed 1,200 calories, potentially leading to weight gain and increased blood glucose levels over time. However, some supplements have a lower glycemic index, which may be beneficial for people with diabetes.
Excessive protein intake can deteriorate kidney function in individuals with chronic kidney disease (CKD), although this doesn't apply to those with healthy kidneys. The 2020 KDOQI guidelines advise adults with CKD to limit dietary protein, while dialysis patients generally do not need to restrict it.
A study by the Clean Label Project found heavy metals, pesticides, and other contaminants in numerous protein powders. Long-term exposure to these toxins may result in serious health issues such as cancer or birth defects. When purchasing protein powder, seek brands that test their products through organizations like NSF Certified for Sport or the Clean Label Project.
Some supplements contain additives like caffeine, creatine, or artificial sweeteners, which can have side effects:
- Caffeine: High amounts can cause tremors, migraines, or sleep problems.
- Creatine: It may lead to temporary weight gain, dehydration, stomach upset, muscle cramps, and is not suitable for people with kidney or liver issues.
- Artificial sweeteners: Generally safe in moderation but can cause gastrointestinal symptoms, particularly sugar alcohols.