Semaglutide and Body Mass

Foreign. Talk about semaglutide. This is somewhat of a public service announcement because I'm hearing a lot of chatter about people saying that semaglutide, which is what causes weight loss, is causing a lot of muscle loss, a lot of muscle mass loss. Be very afraid of that because muscle mass preservation is key to slowing down aging. So I'll talk about a few terms so you can understand scientific literature I'm going to review. So we have body mass index, which is commonly just your height versus your weight. So that's bmi, that's really a crude indicator whether or not somebody's overweight. Because if somebody, let's say, has small bones and small muscles and they're overweight or obese, they appear obese, they might have a lower BMI because their bones are small and the muscle is small. So that's not the best number. Then we've got our weight, which is measured in pounds or kilograms. Another weight is usually broken down to a total weight, fat mass. And there's fat mass, that's both in the visceral fat, which is inside the gut lining. And then there is fat free mass, which is commonly called lean mass. Then there's skeletal muscle mass. These two things are not the same. Fat free mass is everything that is not fat. So for example, your brain, your bones, your liver, your circulating blood volume, your connective tissue, your spleen, and all these enlarge. Not your brain necessarily, but most of the organs enlarge as somebody gets heavier. So for example, somebody weighs 300 pounds, has substantially more circulating blood volume than somebody weighs 150 pounds. And that would be in fat free mass. Skeletal muscle mass refers to pretty much all the muscle except the muscle of your heart. Okay, so let's talk about what the literature has told us because again, I'm hearing this both on popular podcast and people that are opposed to semaglutide or tirzepatide, these weight loss drugs called GLP1 agonists. So first article, diabetologica in 2019. Now these were comparing semaglutide to another similar drug as lower doses of semaglutide that we use for currently for weight loss. And they saw that lean muscle mass went up as a percentage of total body weight and people lost an average of six pounds of weight, but their lean body mass went up as a percentage of their total weight. Now the way that's measured in this case, what's called the DEXA scan sophisticated type of X ray, and even though they lost a Little bit of lean body weight. The percentage of lean body weight went up as a percentage of their total weight. But the total body fat went down as a percentage of their total weight. Next article was in Journal of Endocrine Society 2021. This again was a DEXA scan. For every one pound of fat loss there was a half a pound of fat free mass. Visceral fat, which is the dangerous fat that's inside your guts. That went down 27%. Total fat down 20% in fat free mass went down 9.7%. But the lean mass as a percentage of body weight actually went up. So when somebody loses weight, they're going to have less circulating blood volume. Their bones won't weigh quite as much. They're muscle skeletal system weigh quite as much because it's not carrying so much weight. But it went down much less than their fat mass. So their lean mass percentage improved. And there's a lot of knowledge now that lean mass is a predictor of longevity and health. There's really lean mass as a percentage of your body weight, not total lean mass. So in other words, a person that's relatively small could have just as much longevity as somebody that's taller and bigger. But it's based on their lean body mass as a percentage of their total weight. Next one was a Nutrans 2022, 26 week study. The fat mass was down 3 kg per meter squared. And just to break it down, their body weight went down by about 22 pounds and their muscle weight went down by 3.5 pounds. So body weight down by 22 pounds, muscle mass down by 3.5 pounds and again lean mass was up as a percentage of their body weight. Every one of these studies so far they've gotten more lean. Otherwise they have more lean mass. Skeletal and muscle mass at free medicine as a percentage of their total weight. Next one IS European Study 2023. Fat mass decreased by 15%, lean mass by 5% and again their lean mass as a percentage of the total body weight increased. Next one is a study in oral semaglutide which is not approved in the United States yet. They don't lose quite as much weight, but it does work much higher dose than the injectable dose. 26 week study. In this case there's two oral semaglutide studies which are not available in the United States just yet for weight loss. But their skeletal muscle mass actually went up slightly. We're not sure why that is, but their skeletal muscle mass went up even though their fat mass dropped down so what I just kind of clarify this. There's a lot of buz talk about semaglutide and tirzepatide. In some cases I'm hearing, well, they're making people fatter because they're losing mostly muscle mass. In fact, I was at a weekend meeting, it was a longevity meeting, and a person up there kind of came across as expert, but they really weren't. This was actually a private equity person. He told the group that his meetings with the big drug companies, they find that the skeleton muscle, you lose two pounds of lean mass for every one pound of fat loss. That's totally false. That's a rumor. People are spreading it. It's misleading. And there's a lot of people shooting at these drugs that are so successful for weight loss, really having a big impact on our society. We even look at studies looking at people that have diabetes and cardiovascular disease and if they go on semaglutide, it's estimated they add 1.7 years of healthy life expectancy. So I want to continue to kind of address these things. If there's problems with segue, I want to address those as well. But one of the common thoughts that's making people fatter or making people lose mostly muscle, totally false. You do lose muscle mass when you lose weight, typically, regardless if it's just general weight loss, bariatric surgery or semaglutide, other drugs, you can counteract that with exercise and potentially gain weight, gain muscle weight during weight loss. But you don't really worry about the lean muscle loss during semaglutide use because it's not significant compared to the fat loss. You'll be a leaner person at the end. So this is something I've talked about before. I've done some blogs on it. I'm hearing about this all the time. People are not experienced or not knowledge board and not reading the science are going to catch on to that one negative thing and then go on attack and tell people you shouldn't use this because it's causing the wrong weight to be lost. That is.