The next line of the article after that 40% quote:
> Carla Prado, a nutrition researcher in the Faculty of Agricultural, Life & Environmental Sciences and lead author on the commentary, explains this rate of muscle decline is significantly higher than what is typically observed with calorie-reduced diets or normal aging and could lead to a host of long-term health issues — including decreased immunity, increased risk of infections and poor wound healing.
The rather obvious problem is that these GLP1 agonists don't improve your diet. If you continue to eat a protein and nutrient deficient diet (which is probably a majority of Americans) with caloric restriction on top of that, that leads to excessive muscle loss that you wouldn't see in a weight loss diet. This normally doesn't happen without GLP1 agonists, because these diets are too difficult to stick to for most people. Those who stick to them usually turn to nutritious high satiety whole foods that help combat the negative effects of caloric restriction.
Losing weight without losing muscle mass is very hard. It requires extreme diets like a protein sparring modified fast where 80%+ of your calories are from lean protein while running a 50% caloric deficit. If this research is correct, then using GLP1 agonists shortcuts the feedback loops that make the diets hard to stick to, but they shift the tradeoffs from weight to overall nutrition.
"When a measure becomes a target, it ceases to be a good measure" and all that.
>Losing weight without losing muscle mass is very hard.
I was with you up to here. In my experience it's easy to maintain a huge proportion of your lean tissue during a weight loss diet: Do some resistance training, get some protein, and don't lose weight too quickly.
There's no need to go to the extreme of a PSMF - which will still have you lose a bunch of muscle on account of being too big a deficit. If you can keep your calories reasonable while on a GLP1 agonist, there doesn't seem to be any reason you'll lose an exaggerated amount of muscle.
> If you continue to eat a protein and nutrient deficient diet (which is probably a majority of Americans)
Is it true the majority of Americans eat a protein deficient diet? I always thought there was too much protein in the western diet - nearly at every meals versus how we would have evolved with somewhat limited access.
I'm pretty skeptical of the "this rate of muscle decline is significantly higher than what is typically observed with calorie-reduced diets" claim. I suspect we're comparing apples to oranges rather than doing like-for-like comparisons at equivalent calories.
This is true. I just lost 30 pounds over 3 months and 17% was muscle. I thought I was eating a lot of protein, but I’ve upped it today.
I did an InBody scan the day I started (8/21) and just happened to have done my second one this morning.
I'd like to see the diets in the study that are specified as the "calorie-reduced diets". (Can't seem to find the paper). If it's the same as the Standard American Diet, this muscle loss is quite explainable. I think the mitigation is relatively easy though, if you want to shift the p-ratio, recommending a daily high protein shake would do a lot to stave off muscle loss (and even more if resistance training is applied of course). The exercise addition is probably the hardest to adhere to.
> Losing weight without losing muscle mass is very hard.
Lots of amateur body builders can do it. There are whole training guides about how to lose body fat, but maintain as much muscle mass as possible. Granted, they are probably a minority because they have higher discipline and motivation than the average population.Losing glycogen stored in muscle is not a huge issue IMO, as it should come back fast. Stuff that's easy to gain is usually easy to lose and vice versa.
Nutrient deficient, sure, protein deficient? Probably not.
The claim that "a majority of Americans" eat a protein deficient diet is absurd on its face.
> Losing weight without losing muscle mass is very hard.
Yes it is.
> It requires extreme diets like a protein sparring modified fast where 80%+ of your calories are from lean protein while running a 50% caloric deficit.
I’m not any sort of expert but that sounds frankly, dangerous. I don’t see how you do something like that without damaging your liver.
It’s very possible to lose weight and gain muscle, but you have to be at just the right body composition (not lean and not obese) and then there’s a question of “over what period of time”?
Any duration under a month is probably pointless to measure unless you have some special equipment. Any duration over a month and it’s kind of obvious that it is possible. Eat a balanced diet without junk, work out regularly, and keep the calories to only what is necessary.
Part of the problem is that doctors recommendunhealthy diets and will dismiss healthy diets.
> nutrient deficient diet (which is probably a majority of Americans)
This is bullshit. Literally, I Googled for: what percent of americans have nutrient deficient diet?First hit is some blogspam trying to sell me "Nutrient Therapy". Second hit is CDC: https://www.cdc.gov/nutrition-report/media/2nd-nutrition-rep...
> The Second Nutrition Report found less than 10% of the U.S. population had nutrition deficiencies for selected indicators.
Another thing that people frequently overlook, since post WW2, the US has been "fortifying" grains with essential minerals and vitamins. That means when people eat cereal and bread from the supermarket (usually highly processed), there are plenty of minerals and vitamins. Say what you like about the highly processed part, few are nutrient deficient.Yeah, my four donuts per day fill me up just fine or an extra large milkshake and a burger and I’m done for the day with food is definitely happening for some people. Let’s wait and see these drugs might prove to be very beneficial and more testing definitely needed.
Americans eat a shit ton of protein. No idea where you got idea that from.
> The rather obvious problem is that these GLP1 agonists don't improve your diet
My understanding from initial anecdotes is this is actually literally wrong. Which was surprising to me, too. But people on GLPs tend to prefer more nutritious food (high protein and high fiber). I'm not sure if this has been studied directly in clinical trials yet but I know that food manufacturers have been reorienting their products toward healthier meal configurations in response to the GLPs.
I predicted the exact opposite of this, but so far I appear to have been wrong.