If your fitness and nutrition routine includes munching on your favorite snack and nutrition bars before or after your workout, you’ll really want to pay attention to this alarming news. The Clean Label Project has just released a new report that’s exposed what’s really in snack and nutrition bars, revealing that every single one of the 165 top-selling snack and nutrition bars from 50 leading brands showed detectable levels of heavy metals.
The study, titled the 2025 Snack and Nutrition Bar Category Insights Report, also revealed some alarming findings: certified-organic bars contained 28% more heavy metals than conventional ones, and 97% of the bars in the study exceeded Prop 65 limits for acrylamide, a chemical linked to cancer. The findings of this study are raising major concerns surrounding labeling transparency and consumer safety, especially in a $7.4 billion industry marketed as healthy.
In response to the Snack and Nutrition Category Insights report, the Clean Label Project released a new breakdown, the Clean Sixteen, which identifies the 16 cleanest bars with the lowest levels of heavy metals and other concerning ingredients. These are the healthy nutrition bars you can trust for your pre- and post-workout snacks.
Healthy snack bars

According to the study, the Clean Label Project has identified 16 of the most popular snack and nutrition bars that contain the lowest levels of heavy metals, pesticides, glyphosate, BPA/BPS, phthalates, and arylamines. Of 165 snack and nutrition bars tested, these “Clean 16” were identified to help consumers make more intelligent decisions when shopping for snack and nutrition bars. Fitness and nutrition junkies: Be sure to check the list to make sure your favorite nutrition bars aren’t misleading you with their labeling and marketing claims.
In the realm of snack and granola bars, several of Nature Valley’s popular sweet & salty nut granola snack bars have made the list, including the Nut Cashew and Nut Almond varieties. Kind’s Core Caramel & Almond Sea Salt Granola Bar and Peanut Butter Granola bars have also made the list, offering a healthy (and crunchy) snack you can safely enjoy before or after your workout. While the bars on the list have not yet been Clean Label Project Certified, they offer a healthier solution than many of the bars on the list that contain higher amounts of heavy metals and known carcinogens.
For protein and nutrition bars, bars from several well-known brands in the fitness industry have made the list, including:
- Quest Nutrition’s White Chocolate Raspberry Bar
- Luna’s Lemon Zest Organic Bar
- RXBar’s Coconut Chocolate Bar
- THINK’s High Protein Lemon Delight Bar
- Nick’s Peanut single-serve Keto Bar
Choosing healthy nutrition bars

“This study highlights a growing truth: our current food safety regulations simply don’t go far enough to protect all consumers from the hidden risks of today’s industrial food system,” said Jaclyn Bowen, executive director of Clean Label Project. “We’re seeing widespread contamination—from heavy metals and pesticide residues to chemicals migrating from packaging—yet much of it remains unregulated or overlooked. While the results of this study are undoubtedly concerning, what you do with this information is even more critical. The best answer? Create your own healthy nutrition bars and prepare protein snacks at home to know exactly what you’re putting in your body.