Are there any foods I should avoid while taking metformin?

There are no food contraindications or interactions noted for metformin in manufacturer’s prescribing information.^1-4 The manufacturer’s labels do caution against the excessive use of alcohol, either acute or chronic, because of the risk of lactic acidosis.

Clinical practice guidelines from the American Diabetes Association endorse nutrition therapy as an efficacious and cost-effective component of diabetes care.^5-7 They recommend a healthy eating pattern with the goal of improving or maintaining glycemic targets, achieving weight management goals, and improving cardiovascular risk factors such as blood pressure and lipid levels. Targets should be individualized to patient needs and disease progression. They emphasize the need to address an individual’s needs related to cultural preferences, socioeconomic status, access to healthy foods, and other barriers while maintaining the pleasure of eating and avoiding judgmental or unrealistic dietary guidance.

Consensus dietary recommendations include:⁵

• Eating non-starchy vegetables
• Minimizing added sugars and refined grains
• Choosing whole foods over highly processed foods whenever possible
• Reducing overall caloric intake through limiting carbohydrates

According to the World Health Organization, a healthy diet includes the following:^8-13

• Fruit, vegetables, legumes, nuts, and whole grains
• At least 400 grams (five portions) of fruit and vegetables per day, excluding potatoes, sweet potatoes, cassava, and other starchy vegetables
• Less than 10% of total caloric intake from added sugars (50 grams, about 12 level teaspoons) for a 2,000 calorie-diet, but ideally less than 5% of total energy intake
• Less than 30% of total caloric intake from fat. Unsaturated fats are preferable to saturated fats and trans-fats . Intake of saturated fats less than 10% of total energy intake and trans-fats to less than 1% of total energy intake. Industrially produced trans-fats should be avoided.
• Less than five grams of salt (about one teaspoon) per day

References:

1. Glucophage (metformin hydrochloride) tablets, for oral use & Glucophage XR (metformin hydrochloride) extended-release tablets, for oral use. [Package insert]. Princeton, NJ: Bristol-Myers Squibb Company; 2018.
2. Riomet (metformin hydrochloride) oral solution. [Package insert]. Cranbury, NJ: Sun Pharmaceutical Industries; 2018.
3. Riomet ER (metformin hydrochloride for extended-release oral suspension). [Package insert]. Cranbury, NJ: Sun Pharmaceutical Industries; 2019.
4. Glumetza (metformin hydrochloride) extended-release tablets, for oral use. [Package insert]. Bridgewater, NJ: Valeant Pharmaceuticals; 2018.
5. Evert AB, Dennison M, Gardner CD, et al. Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report. Diabetes Care. May 2019;42(5):731-754. doi:10.2337/dci19-0014
6. ElSayed NA, Aleppo G, Aroda VR, et al. 8. Obesity and Weight Management for the Prevention and Treatment of Type 2 Diabetes: Standards of Care in Diabetes-2023. Diabetes Care. Jan 1 2023;46(Suppl 1):S128-s139. doi:10.2337/dc23-S008
7. ElSayed NA, Aleppo G, Aroda VR, et al. 5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2023. Diabetes Care. Jan 1 2023;46(Supple 1):S68-s96. doi:10.2337/dc23-S005
8. Diet, nutrition and the prevention of chronic diseases. World Health Organ Tech Rep Ser. 2003;916:i-viii, 1-149, backcover.
9. WHO Guidelines Approved by the Guidelines Review Committee. Guideline: Sugars Intake for Adults and Children. World Health Organization; 2015.
10. Fats and fatty acids in human nutrition. Report of an expert consultation. FAO Food Nutr Pap. 2010;91:1-166.
11. WHO Guidelines Approved by the Guidelines Review Committee. Saturated Fatty Acid and Trans-Fatty Acid Intake for Adults and Children: WHO Guideline. World Health Organization; 2023.
12. Nishida C, Uauy R. WHO Scientific Update on health consequences of trans fatty acids: introduction. Eur J Clin Nutr. May 2009;63 Suppl 2:S1-4. doi:10.1038/ejcn.2009.13
13. WHO Guidelines Approved by the Guidelines Review Committee. Guideline: Sodium Intake for Adults and Children. World Health Organization; 2012.