5 Nutrition Myths That JUST. WON’T. DIE.

Chapters:

00:00 1 Fasting is extra healthy because of autophagy

01:39 2 BCAAs

02:38 3 Carbs make you fat

03:29 4 Protein is bad for your kidneys

05:26 5 Creatine causes hair loss

06:20 6. You can’t recomp

09:06 Outro

Transcript:

Myth #1 is that intermittent fasting diets are healthier than diets without fasting because of… AUTOPHAGY! Many proponents of intermittent fasting utter the words like they’re casting a magic spell. The effect of the spell is that the debates you are having with them is instantly ended with them emerging victorious. Here’s the thing… Autophagy is real and it’s great for your health.

Autophagy is basically a cellular cleanup process. You can think of it as internal recycling in your body. It cleans up damaged cells, and it’s great for intercellular repair. However, autophagy is stimulated by any energy deficit. In the only study we have that directly contrasted a fasting diet with a non fasting diet with continuous energy restriction, both diets had similar markers of autophagy. So there is no evidence that fasting diets actually stimulate more autophagy than non fasting diets.

What predicts autophagy in research is the energy deficit. You can get very significant autophagy with any diet that puts you in an energy deficit. So fasting is not required. On average in research fasting diets are no healthier than diets without fasting. To quote a 2024 meta-analysis: “Isocaloric intermittent fasting…”, meaning that you control for energy intake between the two diets, “…is not superior to calorie restriction in enhancing health outcomes in adults and the elderly. The health benefits induced by intermittent fasting are calorie restriction dependent. Intermittent fasting does not provide additional health benefits beyond those achieved by calorie restriction.” So fasting can be great for your health if it puts you in energy deficit, but it’s the energy deficit that really makes you healthier.

Myth #2 is that branched chain amino acid supplements help you build muscle. Compared to absolutely nothing, that is true according to some research. Because BCAAs are protein, and protein helps you build muscle. But the reason that you consume protein is that you get all of the constituent amino acids of protein. Our bodies don’t actually have a protein requirement, we have a requirement for essential amino acids. So when your total protein intake is sufficient and it comes from reasonably high quality sources, you also get enough branched chain amino acids in your diet.

As a result, a 2025 systematic review of 14 studies concluded that: “Leucine supplementation…”, which is kind of the star of the BCAAs, “…does not confer significant benefits in muscle growth, strength, or recovery in healthy, trained young adults.” A multitude of other studies have found that BCAA supplementation on top of a sufficient dietary protein intake, does not help you build muscle or strength. You already get all the BCAAs you need from your diet.

Myth #3 is that carbs make you fat. This is still a very widespread concern in the general population. The research, however, is very clear. There are a lot of studies showing that low carb diets result in better fat loss compared to higher carb diets. However, what happens in these studies is that the people on the low carb diets consume more protein and often also end up with a lower energy intake because of the satiating effects of sometimes ketosis and often the higher protein intake.

When you strictly control for energy and protein intake, and you compare diets that differ only in the degree of carbohydrates, so high carbohydrate-low fat versus high fat-low carb, we see that there is no significant difference in fat loss or weight loss between the groups. So no, carbs do not make you fat. Chronically consuming in an energy surplus is what makes you fat.

Myth #4 is that high protein diets are bad for your kidneys. Again, this myth seems to have some truth to it because if you look at people on high protein diets, then in their urine and in their blood you will see that they have elevated levels of creatinine and nitrogen in many cases. However, this just means that the body is processing more protein. When there is more protein going in, there is more waste products of protein going out, and many tests of kidney filtration function, they also simply rely on these creatinine levels.

If your doctor told you this means there’s something wrong with your kidneys, you should probably find a new doctor, because there is now overwhelming support from multiple systematic reviews and health organizations that have concluded high protein diets are actually safe for your kidneys and overall health.

In fact, a 2024 meta analysis found that high protein intakes were associated with lower incidence of chronic kidney disease, particularly when the high protein intake came from plants or seafood. Even in many studies in people with preexisting kidney problems, high protein diets are safe. However, if you do have an actual preexisting kidney problem, then of course talk to your doctor, yada yada… If you are genuinely concerned about your kidney health as a strength training on a high protein diet, especially if you’re also supplementing creatine, you should check your Cystatin C.

Cystatin C is not influenced by your muscle mass, your activity level, or your age, unlike creating levels, so it is a much better biomarker for us lifters to check our kidney health. A 2021 systematic review of randomized controlled trials found no significant adverse effects of high protein diets in elderly individuals. Moreover, a 2020 meta analysis of cohort studies found no association between all cause mortality and protein intake. Best of all, a 2025 German umbrella review of other systematic reviews found no evidence for an association between either plant or animal protein intake and coronary heart disease, stroke, or total cardiovascular disease risk. This was conducted by the German, so we know it was good work.

Myth #5: Creatine causes hair loss. This myth originated from a small study in rugby players, which found that creatine supplementation resulted in a small increase in DHT levels. DHT levels in the scalp, at least, are associated with more hair loss and early pattern male balding. As a result, this study caused widespread alarmism that creatine supplementation causes hair loss. However, there is no study that has actually reported hair loss as a side effect of creatine supplementation.

Moreover, multiple other studies have failed to find any hormonal effect in the first place of creatine supplementation. And recently a study directly put this alarmism to the test and found that after 12 weeks there were no significant differences between the groups’ changes in hair density, follicular unit counts, cumulative hair thickness, testosterone levels, or DHT levels “…providing strong evidence against the claim that creatine contributes to hair loss.”

Myth #6… Yes, there are 6 myths, even though the title only said 5. That’s because my marketing department tells me you guys have some weird fetish-like distaste for even numbers. You know that’s fucked up, right? That’s like seriously weird. They say influencers are weird, but you guys are not well. Anyway, this one’s on the house.

Myth #6 is that you cannot gain muscle and lose fat at the same time. This is based on a completely misguided understanding of energy balance. Yes, you can only be in energy surplus or in energy deficit, but this says nothing about which substrates your body is losing or building at any point in time. In fact, at any point in time in your whole body, your body is breaking down and building tissues all over the place. So there’s absolutely no reason why your body couldn’t break down fat and gain muscle somewhere else at the same time. This is in fact happening everywhere. And while we’re talking about muscle growth or fat loss over time, all that we’re really talking about is the cumulative balance over time.

There are literally hundreds of studies showing that people can lose fat and build muscle on the same program. And yes, there are also many studies showing this occurs in previously trained lifters. I see it all the time in my clients. I would go so far as to say that if you are intermediate or novice level trainee then you should be recomping on a good program. The fact that we see that even on programs from research which are not optimized, they’re not customized, and they often only have people follow a training program or a nutrition program not to optimize programs at the same time means that it’s in fact rather easy to achieve body recomposition, unless you’re already very advanced.

So I would say that for many individuals, you’re actually doing something seriously wrong if you’re not gaining muscle in energy deficits unless you are an advanced lifter. If you’re losing muscle in energy deficit, you better be super advanced or there’s something seriously wrong. The vast majority of my clients, literally over 99%, continue to gain strength in energy deficit. Research also confirms that strength development, in particular, is not influenced very heavily by being in energy deficit. You should be gaining strength at a minimum because of neural adaptations. Even if you’re not getting much muscle, you’re just clinging on to your existing muscle mass.

That said, it gets much harder to recomp when you’re leaner and more advanced, so a high level bodybuilder is very unlikely to recomp and is, in fact, if they are truly at their natty max, inevitably going to lose some muscle mass over the course of their contest prep. But for most men above 10% body fat, and women above 20% body fat that are not yet near their maximum muscular potential, body recomposition is possible, and in fact quite realistic in many cases.

If you’re interested in an individualized and optimized evidence based strength and nutrition program, then click on the link in the description to get a free program in my MH Physique App to take your physique to the next level. I hope you enjoy it.