There are many people out there that seem to think that the body seeks protein and will overeat to try and fulfill the protein need. They use data which shows that when people eat higher protein they tend to eat less over the course of a day. Like this is actually a good thing. Here is an alternate view point to that theory and why the protein leverage theory is likely wrong.
This graph is from data collected from MyFitnessPal. It shows percentage of calories to target consumed vs percentage of protein in the diet. The insinuation is made that the more protein you eat the less you will eat and this is good.
There are a few issues with this graph and what is trying to be said about it.
- The target calories are often set far too low. It is not uncommon to see calorie targets in these apps as low as 1100 cals. This is starvation level caloric restriction and is not healthy long term. Just for reference, 150lb men where given 1500 calories a day during the famous Minnesota Starvation experiment to see how they would react to a dramatically reduced caloric intake due to food scarcity after the war. These men suffered from various issues such as extreme weight loss, muscle atrophy, food obsession, and mental illness. Many of them had to be committed and one of them even mutilated himself with an ax.
- Is eating that much less than these targets beneficial? It is pretty well established that we can lose weight with caloric restriction. This we know and it has been done by millions year after year. What we also know is that only 2% of those people actually keep it off. The reason for this is actually very simple. You lower caloric intake and your metabolic rate drops to compensate. The bodies primary goal is to not lose weight as this means you are at risk of death. This was the case for all of our evolution and only in the last 50 years or so has it not been an issue because of the massive food availability and the composition of our diets. If you restrict for too long you only make your metabolism lower and if you restrict too much you can do long term damage to this metabolic rate. This was seen in the Biggest loser study. In this study they followed the biggest loser contestants for 6 years and saw that their metabolic rate had dropped an average of 600 calories due to their over exercise and under eating. This caused them all to gain back considerable amounts of weight regardless of maintaining their diet and exercise. If you restrict and exercise you drop your metabolic rate so low that any increase in calories or slight decrease in exercise means inevitable weight gain. This is why calories in vs calories out in these simple terms does not work.
- Are the people eating less because they are satisfied or is this something else all together? This is the beef of the issue and I will get into it in depth.
Is this graph showing satiety or something else?
Those that use this type of data to propose more protein being great are looking at it from the wrong perspective. If reducing calories and increasing protein was the solution and you were only eating less because you are hitting some magical protein number that fulfilled all your needs then why do we see these issues with calorie restriction? Even with huge protein amounts:
- hair loss – This is one of the most common issues I see from people following this low fat, low carb, low calorie and high protein method. Hair falling out by the handfull. Only when they eat more calories does it stop. Protein alone is not enough.
- Bruising – There is one well known proponent of this method that was seen commenting in a group that he was bruising when working out on his low fat/low carb/high protein diet. This is due to excess protein without adequate fat. This is referred to as Rabbit Starvation and it has many other symptoms such as diarrhea, fatigue, headache, low blood pressure, slow heart rate, and vague discomfort that can only be satisfied by eating fat.
- Lowered thyroid function – With all calorie restriction, even with higher protein, you get lowered thyroid function and this is only a protective mechanism to keep you from losing weight. If you resume eating adequate calories thryoid function resumes. It may be possible to do long term damage if caloric restriction is maintained long term.
These are just a few issues with maintain a caloric deficit. What about the opposite side of the coin? The Fat leverage Theory.
Looking at this graph all we see is protein vs calories. It is not comparing a very low carb/high fat diet to a low fat/low carb/high protein diet. The people eating above 100% of their goal are more likely to be eating foods that are highly palatable and those foods are foods that are high in fat and carbs. We are designed to go after those foods because those foods are the foods that will maximize fat storage and fat storage meant safety for pretty much all of our evolutionary history. This is an interesting article about how our ability to get fat allowed us to evolve. This is the problem with just looking at high level data like this. We are making correlations that don’t take into account all factors. Shark attacks are much higher when icecream sales are also higher. Should we avoid icecream to prevent shark attacks? No. Just linking one intake of one macronutrient to overall caloric intake is only 1/100th of the story. This is what is referred to as cherry picking at the highest level.
So these folks like to say that eating higher protein makes you satisfied so you eat less. Well then why do people that go very high fat/low carb/moderate protein also lose almost all hunger? I often see folks eating less than 1,000 cals a day on keto and constantly say they just aren’t hungry. These are always the people that are stalled and can’t lose weight despite eating 1,000 cals a day. Why is this if protein is the magical satiety factor that leads to reduced caloric intake and the magical wonderland of sustained weight loss? That is because reduced hunger is not always a good thing. People that fast often report they feel no hunger as do people that are actually starving. Why is that?
The reason people that fast/starve/caloric restrict seem to lose hunger is a survival mechanism like many others. If a starving hunter gather was plagued by hunger would they be an effective hunter? No. They would be too distracted and likely die. People that fast/caloric restrict/starve also report that they have more energy. Is this a magical effect of ketosis or more protein or less calories? No. It is called epinephrine. Epinephrine is an adrenal hormone and when you are in too much of a negative energy balance your body is pumping this stuff out like crazy in order to keep you upright and alert enough to hunt. Epinephrine is a potent stimulant and like all other stimulants, it reduces hunger and gives you energy. Ask a meth user if they are hungry after they use. They won’t be. They are also usually pretty damn skinny. No I am not comparing caloric restriction to using meth directly. Just the fact that they are both stimulants and they both reduce hunger.
So what about the fat leverage theory being the reason we eat less with more protein intake?
Perhaps the reason people eat less when they consume more protein is because of a negative feedback loop. In nature protein and fat typically came hand and hand. Usually in at least a 50/50 ratio. There are theories that say when you seek out too much lean protein and avoid fat the body actually down regulates hunger to avoid getting too much protein rather than just down regulating hunger because you are getting what you need. Since in nature fat rarely comes without protein, if you were continue to eat you would reach a level of protein that is dangerous such as Rabbit Starvation. There is no such level of fat consumption that is dangerous that we know.
As previously mentioned, fat is needed for the body to function properly and when inadequate amounts are consumed we can suffer the consequences of Rabbit Starvation. I propose that the reason we stop eating when we consume lots of protein is to protect us against protein poisoning. it is not a satiety signal at all. Just a protective mechanism like many others I have spoken about already.
Just to finish off, here is some interesting data on how humans have always strived and worked incredibly hard to get fat. Much harder than anyone ever did to seek out protein.
A taste for fat may have made us human
Origins of the Human Predatory Pattern: The Transition to Large-Animal Exploitation by Early Hominins
As always, if you need help with breaking a stall or just need some help with accountability you can check out our coaching services here: