Why Do You Gain Weight? Hint: It’s Not the Calories
Why do you gain weight?
The prevailing theory is that you eat more calories than you burn. The prescription is to eat like a rabbit — salads for 3 meals a day — and run on a treadmill until your legs cannot function any longer.
Clearly this has not worked, and it’s because our naive conception of obesity is all wrong.
Let’s dig in:
Table of Contents
Calories in Calories Out
The predominant obesity theory is that you gain weight because you consume more calories than you burn.
Yes, technically that is true. It’s simple thermodynamics. If you consume more calories than your body burns, they must be stored somewhere. They don’t vanish into thin air.
This theory is called the “Calories in, Calories out” theory of obesity (CICO for short) and is the reason why people count their calories and are obsessed with how many they burn.
It’s why people’s first approach to weight loss is exercising to increase caloric expenditure.
CICO rules everything around us.
However, the problem is that people have taken a scientific theory made for closed systems and tried to apply it to human beings — an open, complex, and adaptive system. It’s a physics theory naively applied to humans.
The photo below shows the Krebs Cycle, which is how your mitochondria generates energy. Do you see a receptor for a “calorie.” Of course not. Your body doesn’t recognize calories like a car would.
CICO is a superficial way to approach weight loss. Over the long run, IT DOES NOT WORK.
Why Weight Loss Via Calories in Calories Out Doesn’t Work
The CICO theory of weight loss is the embodiment of human arrogance. Pseudo scientists have likened human beings to machines that burn calories like fuel in a car. But the relationship is much more complex and cannot be distilled down to a simple accounting equation.
Just because it’s technically true that calories in has to equal calories out doesn’t mean that using that theory to approach weight loss is optimal. It’s a descriptive theory, rather than a prescriptive one.
There are three main reasons why simply reducing caloric intake and increasing caloric expenditure doesn’t work over the long run.
Here are three:
#1 Calories In Affect Calories In
The type of food you eat affects how much you eat.You cannot control your hunger. You can’t just will it away. It’s controlled by your hormones.
Certain macronutrients and food compounds increase your hunger.
For instance, this study shows that processed food makes you eat more. Subjects in this study consumed 500 calories per day more when they consumed processed foods.
The reasons why are multi fold and I will get into them more below. But the key takeaway is that if you plan to reduce your caloric intake but eat the wrong foods, your hunger will come back with a vengeance.
It’s more unlikely to be sustainable than jumping off a building and trying to fly is. You will lose.
So if you eat 500 calories of Doritos thinking you can run on a treadmill for an hour to burn it off think again — the Doritos will make you hungrier later and you won’t be able to burn body fat..
#2: Calories in Affect Calories Out
What you eat also changes the amount of energy you burn. Calories out is not constant. It is a function of 3 components:
- Basal Metabolic Rate: The amount of energy to power organs like your brain to stay alive at rest
- Thermic effect of food: The amount of calories different foods take to burn
- Active metabolic rate: The amount of energy you expend moving
Of these, the BMR is the large majority of energy expenditure. And doing sudoku puzzles cannot make your brain burn substantially more calories.
To lose weight, most people plug their age, weight and exercise habits into an online calculator to determine their total energy expenditure. But this assumes that BMR stays constant.
This is one of the biggest misconceptions regarding CICO.
BMR is highly volatile depending on the foods you eat.
Dr. Ben Bikman has shown that a ketogenic diet can actually increase your BMR, burning more calories at rest.
How? When you’re in ketosis, your body increases its brown fat content. Brown fat has something called uncoupled mitochondria, which actually wastes energy as heat. This means that you burn more energy than you actually need.
It’s essentially a cheat code for weight loss.
This study showed that participants on a low carb keto diet actually burned 300 calories more per day at rest. That’s like jogging for 30 minutes, just because you reduce carbohydrates.
Calorie counting is a miserable way to live. Instead, if you eat the right foods and allow your body to burn body fat for fuel, you can leverage these satiety mechanisms and your natural mitochondrial uncoupling.
This is why studies have shown that people on ad libitum (eat as much as you want) low carb diets lose more weight than calorie restricted high carb diets.
#3 Your Body is Too Smart to Be Tricked
Similarly, your Basal Metabolic Rate is very sensitive to caloric deficits.
This is one of the biggest reasons why people fail when they arbitrarily lower calories.
Unlike machines in which the thermodynamic equation is applicable, humans adjust their energy expenditure based on how much fuel is available. Your car doesn’t burn energy slower the less fuel there is.
But if you substantially cut your caloric intake and don’t lower your insulin levels, your body’s Basal Metabolic Rate will fall.
The second part of the previous sentence is key. If you don’t lower insulin levels, your body never unlocks your body fat for energy — because insulin signals to your body to store energy. So if you diet by cutting caloric intake, but don’t reduce your carb content, your metabolic rate will fall to prevent you from dying.
This is why most people who cut calories end up gaining all the weight they lost back. You either grow hungry again or feel way too tired to keep it up. For one, your body is too smart to trick it into losing weight.
For instance, say you reduce your caloric intake by 300 calories thinking that the 300 calorie deficit will evaporate off your body in the form of fat. If you do so by eating a high carb diet, you prevent your body from actually burning your body fat.
Thus, the 300 calorie deficit isn’t made up for by burning body fat — you still need that energy — it’s made up for by reducing your metabolic rate. Instead of losing weight, you just become more sluggish.
It shouldn’t be a surprise then that most participants on The Biggest Loser, who attack weight loss from a caloric perspective, gain all the weight back.
Without changing the macro composition of your diet, you will not be able to stave off weight gain.
Exercise is like a fly on the ass of an elephant when it comes to burning fat. And macronutrients are the elephant.
What Really Makes You Fat? The Hormonal Theory of Obesity
How fat you are isn’t a conscious decision just like how beating your heart is not. It’s mission critical for your body fat to remain within a tightly controlled range.
Evolutionarily this makes sense.
If our ancestors were too fat, they’d die from their inability to hunt. Too skinny and they’d die when food was scarce. This is one of the most important homeostatic equilibria that your body maintains.
So why does this equilibrium get disrupted in some people? Why does their body tell them to eat more calories than they need to burn?
It comes down to hunger and the body set weight: both stemming from hormonal balance.
The problem is that normal weight loss fights this innate mechanism. It tells you to stop eating despite your hunger.
It’s like trying to tell your heart to beat slower. Nobody can keep this up over the long run. Maybe other than a vegan who’s sick of eating lettuce…
The alternative theory for why you gain weight — The Hormonal Theory of Obesity — attacks obesity from this perspective. Jason Fung has popularized this theory in his book, The Obesity Code. If you want more information on any of the claims below, please check out his book.
Body Set Weight
Everybody has a body set weight. Like a thermostat, your body works to maintain homeostasis (equilibrium). This is why counting calories is futile. If you don’t change the set weight, your body will just revert to what it is used to.
Your body is designed to maintain certain fat ratios, particularly dependent on seasons. In autumn our ancestors fattened up to store more energy for winter. And in the summer they leaned up to improve their hunting abilities.
Caloric intake alone cannot change your set weight. It’s more tightly regulated than fort knox.
The best example of this is a study in 1995 conducted by Dr. Leibel. He overfed subjects to make them gain 10% more weight. He then returned them to their original weight and had them lose about 10% weight. What he found was that when they were overweight, their metabolic rate sped up to burn more calories and bring them back down to their natural rate. The exact opposite happened when they lost too much weight.
What regulates this process and why does your set weight increase?
Leptin vs. Insulin
The amount you eat is a product of your hunger. If you’re not hungry, you won’t gain weight.
Your body set weight control this process. And body set weight is controlled by insulin and leptin, two hormones.
Insulin is a storage hormone. When you eat, insulin increases to drive energy into storage and create body fat. When insulin increases, body fat burning shuts off because you’re body is too efficient to both create and burn body fat at the same time.
This makes sense and is not necessarily bad.
Whereas Leptin is a hormone produced by your fat cells telling your brain that you’re full. It signals that your fat cells are stuffed and that you can start to burn calories again becuase of the food available.
Leptin vs insulin is the biggest rivalry in the world.
Leptin and Insulin normally reciprocally flux back and forth. After you stop eating from the leptin, insulin falls back to baseline. You and your fat cells are satiated and you can stop eating. Once again, just like breathing, this is not under conscious control. You cannot will yourself to be less hungry.
If all goes well, your body set weight will stay constant and your weight will too.
However, nutritional recommendations over the last 50 years have massively tilted the scale and disrupted both hormones. In turn, the hormone disruption continues to set your body fat thermostat high and higher.
Like a colleague who continues to raise the thermostat temperature behind your back, hormonal imbalances make you hungrier than you need to be to satiate your energy needs.
How does this happen?
Randall Cycle: Glucose & Fatty Acid Antagonism
Quick detour to the Randall cycle. The randall cycle is also known as the glucose fatty acid cycle. It describes how glucose and fat compete for substrates. Meaning, your body can either burn fat or glucose, but not both at the same time.
Your body only has room to store a few hundred grams of glucose. Whereas your reservoir for fat is much larger. Therefore, glucose oxidation takes priority.
If there is excessive glucose in your system post ATP creation, a portion of the remainder gets converted to fat for storage.
Because excess glucose gets stored as fat, it doesn’t make sense to simultaneously burn fat. So glucose and fat are burned reciprocally.
When glucose is present and insulin is elevated, your mitochondria block fat from entering the cell to be converted to energy.
If carbohydrates are eaten occasionally and they are lower glycemic, your insulin levels will normalize and your body will burn fat as fuel. But, as we all know too well, most people eating carbs aren’t doing so occasionally.
So this is why most people never burn body fat despite trying to reduce calories and run on the treadmill all day. If insulin is always high, you can never burn your body fat.
The recommendations to eat 6+ meals a day and replace fat with carbs was a recipe for disaster. Insulin is constantly eating from both the high glycemic foods and the constant “grazing.”
Ultimately, fat cells become overstuffed and it takes more and more insulin to get energy into them. Insulin starts to overtake leptin in the insulin v leptin duel.
When insulin is persistently elevated, fat cells become overstuffed with energy. In response, they secrete leptin which tells you to stop eating. But if leptin is persistently high, its efficacy will decrease over time. Ultimately, you approach a stage of leptin resistance.
Obese subjects are almost uniformly leptin resistant [*].
Now strap in for the roller coaster. This habit of constantly eating insulinogenic foods creates persistent insulinemia (high insulin levels) and an ineffective leptin response.
Leptin is like a stop sign. Because it no longer works, this makes you even hungrier for the same foods that destroyed your health in the first place.
And to throw fuel on the fire, refined carbs have been shown to increase another hormone, called ghrelin, tat makes you even hungrier after eating them.
Think about bread at a meal. Every wonder why restaurants always serve it to you at the beginning? Does it ever really fill you up? No. Most people turn into a bottomless pit, deeper than the Grand Canyon when they start eating bread.
To summarize: eating 6 meals of high fat & high carb meals a day, overstuffs fat cells, leads to persistently high insulin levels and to leptin resistance. This resets your body set weight higher, increases hunger beyond caloric needs and increases weight gain.
It’s not a willpower problem. It’s a hunger problem.
Protein Leverage Hypothesis
Now that you’re with me that obesity is a hunger problem, not a willpower problem, let me present one additional hypothesis why people are eating too much.
Humans have a very strong protein drive.
Part of the insidious impact of the recommendation to cut red meat and replace it with carbs is the drastic reduction in protein.
Back when we were hunter gatherers we ate a very high protein to energy (carbs and fat) diet. But now thanks to the introduction of big CPGs weapons of choice — sugar, flour and vegetable oil, all abundant energy sources – energy has gone up massively compared to protein.
Now, over 40% of Americans get insufficient protein [*]. It’s fallen to 10% or less of calories.
This is where the protein-leverage hypothesis comes in.
Without knowing it, humans search for 15%+ of their calories from protein. When we lower it, even just slightly, our body massively overcompensates with lower satiation and increased carbohydrate and fat intake. This study pictured below showed just a 1% decrease in protein led to 14% increase in CHO + Fat intake [*]
So if you’re not getting enough protein, you continue to eat until you satisfy those needs. This usually means you’re eating too much.
This is exactly what has happened and is part of the reason why you could eat 2000 calories of doritos without breaking a sweat, but it would be much harder to do with steak.
Seed Oils Are Also to Blame
Lastly, I can’t finish this post without addressing one of the most evil villains: seed oils.
Why do seed oils cause fat gain? For one, HNE triggers fat accumulation by altering fat tissues. This study in C. Elegans — a yeast — showed that HNE signaled to cells that they should be storing fat instead of burning it.
Another study in rats tested 3 diets composed of varying amounts of soybean oil. The percentages ranged from 1% to 22%, which is representative of the western diet.
Calories were identical but all three test groups gained more than twice the amount of weight. Just 1% of calories from linoleic acid can induce weight gain. There is no such thing as moderation here…
Whereas Omega 3 acids encourage beta oxidation — burning fat for fuel — omega 6 fatty acids suppress it [*].
This study showed that seed oils increase insulin concentrations in rodents [*]
Seed oils, which are part of the Mt. Rushmore of foods on the western diet, add fuel on the fire.
To Summarize: Mainstream Dietary Recommendations Make You Gain Weight
Why is over ⅔ of the US overweight today? Because all current nutritional advice increases hunger and insulin levels. Every single recommendation has increased your body set weight, and caused you to eat well beyond what you require. Seed oils have decimated fat burning capacity, and high glycemic, low protein foods incessantly spike hunger.
For the last 50 years we’ve all been lied to. You’re not overweight because you’re lazy or not exercising enough. You’re overweight because you’re eating foods that throw off all of your innate weight regulating mechanisms.
Processed food companies want you to believe you’re fat because you’re lazy and consume too many calories. Not because their junk food manipulates your endocrine system to make you hungrier.
This diet with excessive refined grains and constant eating is a recipe for disaster. It tilts your body towards excessive fat accumulation and ensures that you’re always hungry. All it does is funnel money into their pockets, at your expense.
If you wanted to design a perfect diet to perpetually increase hunger it would be what most people eat today.
A calorie is not a calorie is not a calorie.
If you want to hit the reset button on your body set weight, it should start with the carnivore diet.
The carnivore diet is the most powerful diet for weight loss in the world. 1000s of people have lost 50+ pounds with this way of eating.
If you want to continue this journey and start improving your health, check out the getting started with the carnivore diet guide I prepared for you by clicking the button below.