Weight-loss drug found to shrink muscle in mice, human cells

The modern weight-loss programs I'm seeing now (at least those aimed mostly at middle-aged men) emphasize consuming significant amounts of protein (2g for every 1kg of body weight each day) and engaging in regular resistance training, in order to maintain muscle mass.

The article addresses this:

To keep muscle strong while losing weight, Prado says it is essential to focus on two main things: nutrition and exercise. Proper nutrition means getting enough high-quality protein, essential vitamins and minerals, and other “muscle-building” nutrients. Sometimes, this can include protein supplements to make sure the body has what it needs.

Perhaps there needs to be more formal research into this, and a strong recommendation made to everyone using these drugs that this kind of diet and exercise plan is vital.

At 40% muscle loss you're getting awful close to losing weight while increasing your body fat percent!

But of course you're right that diet+exercise is key but for those maintaining such, they wouldn't end up on these drugs to start with.

This comes from professional bodybuilding, where people are using steroids, along with various, uh, interesting chemicals on the cut[1]. It has almost no benefit to (real) natural bodybuilders. It's closely tied to cycles of steroids.

[1] Ephedrine, Albuterol, Clenbuterol (literally only approved for horses in the US), DNP, and probably more that I haven't heard of. Here's an NIH article on the dangers of DNP, to put it in perspective: https://pmc.ncbi.nlm.nih.gov/articles/PMC3550200/

Outside of noob gains it is incredibly difficult for a natural to add muscle mass when in a calorie deficit and recomposition at maintenance calories is also inefficient in the vast majority of cases.

They won't bulk the same way someone on gear does, but it's still the most efficient way to add muscle mass in the vast majority of cases.

No, they don't. They simply eat enough to continue muscle growth and attempt to shed fat before a competition. Any non-competitor doing this is just engaging in quasi-religious nonsense or rationalizing a bad diet.

Bulking and cutting have meaning, and we're not going to turn it into any caloric surplus vs deficit.