The Hidden Thermogenic Effect of Protein

by Chris Shugart

Protein Syntheses, Thermogenesis, and Metabolism

How much protein can you eat in each meal? As much as you want. You'll only get leaner. Here's why.

The fitness world is haunted, not by ghosts but by bad and outdated ideas. And no matter how educated we become, we hear them rattling their ethereal chains.

Here's an example: A while back, I wrote about increasing your calories just enough to support optimal muscle gains without adding too much body fat. I suggested a simple daily 500-calorie shake. I ran the macros and saw that the shake contained about 53 grams of protein. That's when my internal EMF meter went off:

"But wait, can I absorb that much protein in one sitting? Won't excess protein turn to fat? Will I get pudgy and lose my OnlyFans subscribers?"

I knew this was just a bad-idea ghost, but I had to reassure myself. I dove into the research and found a few things that helped purge the poltergeist.

Protein Syntheses vs. Thermogenesis

You've heard for years that most lifters need roughly 25-40 grams of protein per sitting, depending on their body weights, to optimize muscle protein synthesis, the process of growing new muscle tissue. That's true, but this discovery summoned a lot of ghosts.

Based on these protein synthesis studies, some well-meaning experts chose a number in the middle, like 32. All you need is 32 grams of protein per meal. Any more than that does nothing. Or worse, the excess protein gets "converted" into body fat. So 32 grams became "the rule."

For bodybuilders or athletes trying to consume about a gram of protein per pound of body weight, that meant eating six meals per day. That, too, became "the rule." Then we all started lugging around Tupperware containers of tuna and setting alarms to eat every three hours. Good times.

The problem? Mainly, this: the 32 grams per meal rule was based *solely* on muscle protein synthesis. Yes, there is a ceiling. Past a certain point, extra protein won't boost MPS much. But (and this is a big hip-thrust-built *but*) it also won't turn into body fat. In fact, the opposite is true. That extra protein actually makes you leaner by increasing thermogenesis.

The Study

Researchers had a bunch of overweight men and women consume either 30 or 50 grams of protein. After, they measured their metabolic rates for over five hours. Energy expenditure was measured by indirect calorimetry. They also collected blood, breath, and urine samples to measure substrate oxidation and other metabolic parameters.

What happened? The group who consumed 50 grams of protein experienced a sweet boost in metabolic rate. The thermic effect was 34% higher than that of the group eating just 30 grams of protein.

Smart-guy types call this *diet-induced thermogenesis*, and it's related to TEF or the thermic effect of food. As you know, protein has a much higher TEF than carbs or fats. Digesting and assimilating protein generates lots of heat and burns up lots of energy/calories – thermogenesis in a nutshell.

In a related study of weight-lifting men and women ingesting 800 extra daily calories from protein, not a single lifter gained fat, even after 8 weeks. Diet-induced thermogenesis certainly played a role there.

What Does This Mean to You?

It means you can forget the old rules. Bill Campbell, Ph.D. summed it up like this:

"This finding is really neat because it lets us know there's not a threshold (or ceiling effect) for the amount of protein you can ingest in one meal and its ability to increase your metabolic rate response."

I like to think about it like this: The first 25-40 grams of protein in a meal helps me build muscle; anything over that helps me stay lean.

A little simplified? Yes. But the ghosts have been exorcised. This house is clean.

This also fully supports the protein-first eating strategy. Revolve your nutrition around protein, eat about a gram of protein per pound of body weight, and the rest of your diet pretty much autoregulates and falls into line with your goals: more muscle, less fat.

My approach is to have two MD Protein (Buy at Amazon) shakes per day, either between meals or as meal replacements. Each shake contains 42 grams of protein or more if I add extra goodies. And now I know that I don't need to worry about those "excess" grams in each shake. They just help keep the body fat off. They're also delicious.



  1. Jassis, et al. Effects of protein quantity and type on diet induced thermogenesis in overweight adults: A randomized controlled trial. Clin Nutr. 2019 Aug;38(4):1570-1580.

This is SUCH a huge topic of discussion. So glad it’s being brought up here. Mark Bell has made an interesting argument that the idea that there are “4 calories per gram of protein” might be factually true but isn’t practically true. Because of the amount of work the body undergoes in order to DIGEST protein, you may EAT 4 calories of it per gram, but you only end up absorbing MAYBE 1 calorie: the rest is expended in the digestion process. Those numbers, are, of course, just estimates, like everything else, but it speaks to the very argument being presented here.

And it’s so patently stupid to think that our bodies DON’T have some sort of mechanism in place to use food as some sort of fuel. People refuse to employ nuance in the discussion of nutrition, thinking only of macros and not micronutrients, thinking only of protein synthesis and not glyconeogensis or any of the other fascinating biological mechanisms at play.

Can definitely support the benefits of Metabolic Drive in pursuit of driving up protein intake and staying lean. My own experience with the Velocity Diet proved just that, along with the SATIATING benefit of taking in a protein rich diet. Alongside that, it’s the perfect “hunger test”. If I ever think “I’m hungry”, and it’s outside of my meal times, I allow myself to only consider protein options. Metabolic Drive, egg whites, VERY lean chicken breasts/piedmontese steaks, etc. If I don’t want those things, then I’m not REALLY hungry: I’m just bored.


Very true. You know, I was going to dive deeper in the article and look for a “ceiling” with protein per sitting. I’m sure it exists, and this article talked about 50 grams, but that’s just the number they decided to test. What about 55 or 60 grams in regards to metabolic rate? Then I realized that it’s not something we need to worry about because of the satiating effects of protein. Basically, we’d be too full to ever hit the “too much protein” mark anyway.

Good strategy. I’ve also started to ignore the clock and focus on physical and mental energy. Because my diet is basically the protein-first strategy, I seldom get really hungry (actual empty-stomach mechanical hunger), but I do notice an energy dip. Like, if I’ve had over 85 grams of protein before lunch, I don’t feel hungry and I don’t look at the clock to eat just because you’re “supposed” to eat at 12PM. Later, I register the energy dip and have my after afternoon shake around 2 or 3.

That also taught me when to call it a night and go to bed. I start to feel snacky even when my belly is still full from dinner. Most of the time, sure enough, it’s past my usual bedtime. So it’s not hunger; it’s an energy dip, one I should be feeling because it’s time to crash. (My pre-bed 4 capsules of Flameout actually zap what little real hunger I may be feeling before sleepy time.)

This also helped me with a problem I’ve always battled. I call it procrastination eating. I’m pretty good at not eating out of boredom, but I do catch myself procrastinating a big project by saying, “Well, this is going to be a nightmare task… time for a snack!” Now I check myself – “Any energy dip?” If the answer is no, then I know I’m just avoiding a mentally taxing task. That Chris Shugart guy… gotta stay on top of him!


That is absolutely true. And I’ll go one step further…

Because protein basically can’t be stored as fat can we really account for the caloric content of protein the same way as for the caloric content of nutrients that can easily be stored as fat?

I think not.

Let’s look at fat storage from protein.

While it is not physiologically impossible to store protein as fat, it is about as unlikely as me dating Taylor Swift.

First, protein would need to be converted into glucose. This can be done, but at about a 40-50% efficiency rate as not all amino acids can be turned into glucose. This process happens in the liver and it is called gluconeogenesis (meaning creating new glucose).

Then you’d need to convert that glucose into fatty acids to be stored in the fat cells. This part the body is fairly efficient at doing.

But the thing is that both happen in basically opposite environments.

Protein (more precisely, amino acids) will be turned into glucose when glucose is low and you don’t have enough stored glycogen to release glucose in he bloodstream.

Gluconeogenesis happens when your available glucose is low and when you don’t have enough stored glycogen in your muscles or liver to be released as glucose.

If it has sufficient muscle or liver glycogen, the body will use that to produce glucose, not protein.

Ok so that’s one “environment”: protein will be converted to glucose IF blood glucose is low AND if glycogen stores are low or even depleted.

Now, glucose/carbs are preferentially stored in muscles and liver (it is much easier than to store it as fat). As long as there is “room” to store glucose in the muscles or liver, it is unlikely to be stored as fat.

You will store glucose as fat if the glycogen stores are full.

See how both situations are unlikely to happen at the same time?

If glycogen stores are full, you aren’t likely to convert protein into glucose (which is a necessary first step to store it at fat).

If glycogen stores are low or depleted, you might convert protein/amino acids into glucose. But because you have room to store excess glucose in the muscles or liver, you won’t store it as fat.

Bottom line, it’s practically almost impossible to store protein as fat.

Now, when we discuss calories in our field it is mostly as a way to plan for increasing or lowering body weight.

But if a certain nutriment cannot be stored as fat, should it really be factored in like the other nutrients when it comes to establishing caloric balance?


For a long time I wondered why even during the winter I would often wake up very sweaty, then I realized I had started consuming more protein slow and fast digesting before bed duh lol

Really appreciate you taking the time to lay that all down. That really shines a light on the whole situation. And, of course, as a low-carber, it helps me validate my lifestyle, haha. But my most recent experience on a 6 night cruise where I absolutely feasted on protein and fat and came home leaner than I started was also a great n=1 study on the subject.


Another thing worth mentioning, even though it’s not 100% on-topic, is that keeping insulin low increases metabolic rate/energy expenditure and, on the other hand, jacking up insulin slows it down.

That doesn’t necessarily go against a calorie is a calorie argument. BUT hormones (including insulin and T3) can impact daily energy expenditure, which does affect te calories in vs calories out formula.

Keeping insulin high can reduce daily caloric expenditure by a good 300-400kcals. Which makes it harder to be in a deficit.


After years of tracking macros I have also found that high protein, high fat doesn’t put weight or fat on my frame. For me personally, I have a very similar experience like what you saw on the cruise. Sadly, high carb, high fat (and consequently lower protein) tends to pack on the lbs quickly, at least that has been my experience.

Yeah, I think that this is an important observation. Two observations in fact:

  1. High fat and high carbs at the same time is the “secret” to storing lots of fat
  2. Low protein exacerbates everything my keeping you more hungry and typically making you feel worse and likely to lose muscle (less muscle means easier to store fat)

I find that low fat, higher carbs, high protein works (as long as you don’t exceed your glycogen storage capacity) and lower carbs, higher fats and high protein works too.

Most people who say that they gain fat super easily from carbs, are really consuming foods or meals that are high in carbs and fat


Don’t mean to hijack this protein topic, but no longer making ZMA??? Come on Tim or TC???