The Research on Muscle Loss and Weight Regain
Contributed by Stephanie Figon, MS, RDN, LD
Wegovy, Ozempic, Saxenda, Victoza, Rybelsus, Mounjaro, and Zepbound. These new GLP-1 medications are suddenly being advertised everywhere. They are very popular because they are very effective— not only because people lose weight, but because these drugs greatly improve metabolic health and type 2 diabetes.
As a Registered Dietitian Nutritionist now in my 10th year in the Koslosky building at Alaska Weight Management and Diabetes Counseling, I’ve seen many initially promising weight loss strategies fall from grace. From Phen-Fen causing heart valve damage and Oprah regaining weight after her Optifast diet in the 1990s, to the weight rebound after HCG injections and even bariatric surgeries.
While I am very glad these newer medications exist, some research has come out that suggests they have some issues that users need to be aware of.
GLP-1 stands for glucagon-like pep- tide-1. This hormone is made naturally in small amounts in the gut. It slows stomach emptying, so it helps regulate blood sugar and appetite. GLP-1 medications work by mimicking this hormone. They make people feel full sooner and for longer, leading to fewer calories consumed throughout the day.
The lack of appetite helps many people lose 10 to 15 percent of their body weight or more. The changes can be dramatic and relatively effortless, which is why these medications have gained so much attention.
But not all the weight lost is body fat. In a multicenter clinical trial funded by the makers of Ozempic, the STEP 1 study showed that those who received semaglutide (aka Ozempic/Wegovy) had a decrease in lean body mass of ~9.7% and a loss of 10.4% of their fat mass (PubMed Citation: PMID: 33567185). So, depending on body composition, the lost weight might be as much as 40% lean body mass. This includes muscle tissue and organs that play a key role in metabolism and physical strength. This lowers metabolic rate, worsens insulin sensitivity, and makes it easier to regain weight. To prevent this excessive muscle loss, people losing weight need both resistance training and high protein intake.
Many people are attracted by the idea that the medications may greatly help with weight loss, but don’t like the idea of staying on it for the long term. The STEP 1 Trial Extension showed that one year after stopping semaglutide, participants had regained two-thirds of the weight they had lost. What’s more is that they lost most of the metabolic benefit when the weight returned (PubMed Citation: PMC9542252).
So, it appears that like most temporary weight loss diets, GLP-1 medications can be very effective in the short term while a person is actively using them. Yet, the larger problem has always been figuring out what contributed to a person’s current weight and which habits need to change to keep it off.
Life is so hectic, stressful, and distracting that most of us are only loosely aware of just what we are eating or how much. Snacking, restaurants, sugar, hormonal influences, poor sleep, calorie-dense foods, and stress eating will all contribute to one degree or another, and it can be complicated to figure out which factors are most critical.
The good news is that preventive care benefits under commercial insurance cover 100% for nutrition counseling for anyone with a BMI over 30, which is about 40% of the population. A nutrition professional can act as a guide to help you discover the tools and strategies that are necessary for long-term weight loss. It’s important to incorporate these principles into long-term weight management because carrying extra weight is much more of a metabolic problem and a looming financial problem than a cosmetic problem.
Half of adults in the U.S. have either diabetes or pre-diabetes and many don’t know it. According to a 2022 estimate, the yearly cost of medical care for a person with diabetes is estimated to be $12,022 above the average medical expenses for those without diabetes. Some costs can’t be calculated, like those related to poor health and lost quality of life. Prevention pays: weight loss and increased physical activity can delay, prevent, and even reverse diabetes.
Weight loss medications or focused dieting efforts can be important tools to achieve immediate metabolic benefits, but they generally aren’t enough to keep weight off. The bottom line remains that the long-term food choices and lifestyle changes are still the larger issue.