253: The 6 Keys to Building Muscle and Living a Long and Healthy Life | Layne Norton, PhD

We have about, like, over a half-century of research now on artificial sweeteners, and really, the only time we can tie them to any kind of disease is cross-sectional data and when we give rodents super high doses of artificial sweeteners.

What they showed is that, yes, you can build muscle and lose fat, but you will never do either thing to the best of your ability if you're trying to do both at the same time.

I think there's three studies now where they showed that in a calorie surplus where they match protein and match calories, you don't quite accrue the same amount of lean tissue on a ketogenic diet as you do... with a sufficient amount of carbohydrate...

If you look at longevity after age 65... it is extremely striking how closely your lean mass is tied to your longevity after age 65.

Muscle's like a metabolic sink. It's very greedy. So, if you have more muscle tissue, you get away with a heck of a lot more.

The vast majority of the benefits from diets, at least in the context of people going from obese to getting them metabolically healthy, is from the weight loss. Because excess adipose tissue is inflammatory—it secretes all kinds of [inaudible] that negatively interfere with all kinds of feedback signaling.

They basically compared, okay, let's replace sugar-sweetened beverages with either water or artificially-sweetened beverages, and let's also compare those two against each other. Artificial sweeteners not only led to significant weight loss compared to sugar-sweetened beverages, also compared to water.

If you want to lose fat, it is going to require some form of restriction. But you should pick the form of restriction that feels the least restrictive for you and understand that won't be the experience of everyone.

So, in humans, do I think fructose is a problem outside of the calories it contains? No, I don't.

If you are low in energy, your body is less likely to spare that protein for lean mass accrual because it's sensing an energy deficit. So, it's more likely to oxidize that protein or convert it to energy substrate, because, at the end of the day, if we're weighing two things, the first being survival and starvation versus building lean mass, I mean, there's just not the impetus to build a whole lot of lean mass if you're restricted.

There is a very big difference between somebody who is in a controlled surplus while resistance training or doing exercise in order to accrue lean mass than there is somebody who's just sitting on the couch, munching down potato chips.

If you're eating a high-carb diet, yes, you're going to have much lower rates of fat oxidation, but you're also not going to be storing much fat. If you have high fat intake, low carb intake, you're going to be burning a lot of fat, but you're also going to be storing a lot of fat.

I actually did a podcast a while back where I was talking about a survey they did of obese women and found, I think, 60% had some form of sexual assault or severe sexual trauma in their lifetime.

There's almost no satiety effect from soda. People just add that on top of their regular diet. It is literally the first lever I pull when I deal with somebody who's overweight or obese.

One thing that we can say for sure: Artificial sweeteners don't make you gain weight. And based on the research, you actually get a little bit of weight loss.