Bariatric surgery is for severely obese individuals who have not been able to lose weight by calorie restriction. Generally, bariatric surgery is not recommended unless you have serious obesity-related health problems. The surgery makes the stomach smaller and sometimes changes the small intestine. More than 200,000 people per year in the United States have bariatric surgery.
Types of Bariatric Surgery
Three types of bariatric operations are used most commonly: gastric band, gastric bypass, and gastric sleeve. Each type of surgery has advantages and disadvantages.
Benefits of Bariatric Surgery
Bariatric surgery can improve many obesity-related health problems. These include type 2 diabetes, high blood pressure, unhealthy cholesterol levels, and sleep apnea. Weight loss may also improve physical function.
Side Effects of Bariatric Surgery
Bariatric surgery may cause infection, diarrhea, nutritional insufficiencies, and hernias. The Longitudinal Assessment of Bariatric Surgery (LABS) program of the National Institutes of Health tracks the outcome of a large number of individuals who have had bariatric surgery. This program has found that approximately 4% of individuals have at least one major adverse outcome within a month of surgery. There is no difference in adverse outcomes with different bariatric procedures.
Bariatric Surgery and Body Composition Changes
Bariatric surgery causes weight loss in most individuals, and the greatest percentage of that weight loss is a reduction in fat mass. However, lean body mass is also reduced by approximately 20%. Lean muscle lays the foundation for successful weight loss and maintenance, as well as optimal health. The use of a dietary supplement of essential amino acids can minimize the loss of lean body mass from bariatric surgery.
Essential Amino Acid Supplements and Weight Loss Following Bariatric Surgery
Weight-loss following bariatric surgery is fundamentally governed by the same principles that govern any other weight-loss program. Weight is lost because are creating a negative energy balance. In other words, the amount of energy you consume throughout the day is less than the amount of energy you expend. Calories are the unit of energy, so negative energy balance means that caloric intake is less than caloric expenditure.
Losing weight isn’t as simple as dropping pounds. The type of pounds shed is definitely worth its weight!
You want to lose fat and preserve muscle, so all weight lost should be entirely in the form of fat. That’s successful weight loss. Unfortunately, when you reduce the number of calories you eat, you potentially affect muscle mass negatively in two ways.
1. Protein Intake
If you do not change the composition of your diet, you’re going to half your protein intake alongside your caloric intake. You need to keep your protein intake high in order to preserve lean muscle mass during weight loss. In order to do so, you’d have to double the percent of calories you eat as protein, just to maintain the same amount of dietary protein intake that you normally eat. For example, if you consume 25% of your calories as protein, to keep protein levels constant during weight loss, 50% of the calories you eat need to be protein. Given that most protein foods provide at least half of their calories as carbohydrate and/or fat, your entire diet may have to be composed of foods from the protein food group.
The second aspect of a negative energy balance is that it is much harder to maintain the rate of muscle protein synthesis when calories are cut. We’ve known for more than 100 years that the amount of protein needed to maintain a balance between protein synthesis and protein breakdown is influenced by energy intake, which fuels the energy cost of protein synthesis. When you reduce the number of calories you eat, muscle protein is inevitably lost. This is the fundamental challenge of maintaining muscle mass when you are losing weight.
How does all this play out with bariatric surgery? Muscle can only be preserved following bariatric surgery if an adequate amount of essential amino acids (EAAs) are available to stimulate muscle protein synthesis sufficiently to maintain muscle mass in the circumstance of a negative energy balance. The most effective and practical way to accomplish this goal is to base your diet on EAA intake.
The loss of lean body mass and muscle mass, in particular, is dramatic following bariatric surgery. This undesirable effect, in part, reflects an impaired ability to digest intact protein food sources effectively, especially in the first few weeks after surgery. In addition, patients that go through any surgical procedure may develop anabolic resistance—intact protein loses its normal effectiveness in stimulating muscle protein synthesis.
Unlike intact proteins (such as dietary proteins like meat and eggs), free EAAs are extensively digested and absorbed even after bariatric surgery, so their effect on muscle protein turnover is fully retained. The fact that free EAAs can be formulated to overcome anabolic resistance is another potential advantage of relying on EAA-based nutrition following bariatric surgery.
How Many EAAs Are Needed to Maintain Muscle Mass After Bariatric Surgery?
You need to consume at least 1.2 grams of protein per kilogram of body weight each day to maintain muscle mass during weight loss. If you’re 350 pounds, you need to eat 190 grams of protein, or about 400 grams of protein food sources, such as meat, fish, dairy, etc. That’s about 2,000 kcal entirely as protein food sources.
Here’s the challenge: The normal total caloric intake during weight loss following bariatric surgery is about 1,200 kcal/day. It’s clear that the numbers don’t add up—you can’t eat enough protein food sources to maintain lean mass. This is particularly relevant in the circumstance of bariatric surgery, as the nature of dietary intake after surgery is limited.
This disadvantage can be remedied by supplementing with a free EAA formula. EAAs are proven to help you lose the fat while retaining the muscle!
A protein intake of 190 grams per day to maintain muscle mass during weight loss translates to about 80 grams of EAAs, given the normal proportion of EAAs in high-quality dietary proteins. In the early phase after surgery, it may not be feasible to eat more than 50 grams of protein per day, or about 20 grams of EAAs in the form of dietary protein. In order to maintain lean body mass in this circumstance, your diet would be coming up 60 grams short of enough EAAs. To make up the difference, it’s necessary to consume 60 grams of EAAs in the form of a dietary supplement.
It’s as simple as taking a 15-gram dose of EAAs five times a day. A recently published study showed that 5 X 15 grams of EAAs maintained lean body mass during weight loss. As the intake of dietary protein increases with time, the amount of supplemental EAAs required to maintain muscle mass declines, but an intake of at least 30 grams of EAAs will ensure continued maintenance of muscle mass.
If you think you or a loved one may be a candidate for bariatric surgery and would like more information on the different procedures available, as well as what to expect before, after, and during the surgery, I encourage you to visit the ASMBS website. If you are considering bariatric surgery, I recommend exploring essential amino acid supplementation to support your nutritional intake during recovery and beyond.