Guest blog by: Lillian Craggs-Dino, DHA, RDN, LDN, FASMBS-IH, CLT Losing lean body mass (also known as muscle) is a common side effect of aging, dieting, injury, weight loss, and metabolic and bariatric surgery. After surgery, the goal is to lose weight, mostly in the form of body fat, not muscle. However, it’s not possible to lose only fat during weight loss. Losing too much muscle can slow your metabolism, increase the chance of regaining weight, and affect your overall health. The good news is that there are simple nutrition and lifestyle habits that can help protect your muscles along the way. The Importance of a Bariatric Diet Anyone who undergoes bariatric surgery should follow a specific bariatric diet to help with weight loss, support muscle health, and prevent vitamin and mineral deficiencies. A good bariatric diet focuses on: Protein Fluids Vitamin and mineral supplements A balanced variety of healthy, nutrient-rich foods Factors That Contribute to Muscle Loss Several things can make it harder to maintain and rebuild muscle after bariatric surgery, including: Not eating enough protein Hormonal changes, like lower testosterone Eating too few calories Cutting out too many carbs and healthy fats Not doing resistance, strength, or weight-training exercises Protein Recommendations Protein is one of the most important nutrients for keeping and building muscle. Minimum recommendation: 60 grams per day after bariatric surgery1 Individual needs: Based on your surgery type and activity level, you might need more. A registered dietitian nutritionist (RDN) can help determine your needs, often in the range of 1.2-1.5g/kg of body weight. Good protein sources include: Seafood, poultry, eggs, lean red meats, and low-fat dairy. These complete proteins also contain leucine, an important amino acid that helps with muscle growth. It’s also important to eat enough calories overall. If you don’t, your body might break down muscle for energy. The Role of Carbohydrates and Fats Carbs and healthy fats aren’t the enemy—they’re essential for muscle health too. Complex carbs from whole grains, starchy veggies, and fiber-rich, lower-sugar fruits (like berries) give your muscles energy and help with recovery. It’s helpful to eat carbs before and after exercise for best results. A dietitian can help you figure out the right amount for you. Healthy fats, especially omega-3s from fish like salmon, are great for your joints, circulation, and muscle nourishment. Vitamin D is also important—it helps keep bones strong, supports your immune system, and plays a role in muscle and hormone health. Many people are low in vitamin D before and after surgery, so it’s a good idea to get your levels checked. Exercise Recommendations Physical activity, especially strength and resistance training, is key to building and protecting muscle after surgery. The American Heart Association recommends:2 At least 150 minutes of moderate-intensity aerobic activity per week OR 75 minutes of vigorous aerobic activity per week OR A combination of both, spread throughout the week Plus: Include muscle-strengthening activities like weight lifting, resistance bands, or bodyweight exercises at least two days per week. Conclusion While some muscle loss is a normal part of losing weight, the goal is to keep it to a minimum by: Sticking to a bariatric-specific diet Meeting regularly with a dietitian Adjusting your eating and exercise plan as your body changes With the right nutrition, daily supplements, enough calories, and a balanced exercise routine, you can protect your muscles, boost your metabolism, and stay strong during your weight loss journey. References 1. Romeijn MM et al. Nutr J. 2021;20(1):27.2. American Heart Association. Accessed on June 20, 2025, from https://www.heart.org/en/healthy-living/fitness/fitness-basics/aha-recs-for-physical-activity-in-adults.