> It you a eat a lot of fat you will get fat too. Its all about moderation. If you eat 4000 calories of FAT everyday you will get fat

Calories-in-calories-out without considering the hormones that drive both satiety and crucially fat-storage-vs-fat-mobilization (and thus drive both how many calories are craved and how many are burned) is misguided. CICO isn't wrong, but for all practical purposes what drives CICO in real life are those hormones, which are in turn affected by the ratio of fats and carbs in diet: chiefly insulin and leptin. How those are affected by 4000kcal-of-carbs-low-fat (badly) vs 4000kcal-of-fat-no-carbs (benign/beneficially) is easy to find out.

4000kcal of fat and low carbs, if one could stomach it for years, after a few weeks of keto-adaptation? They'd be a tad little bit fatter than they'd like, and feel profusely hot and sweaty. As their leptin and insulin sensitivity gets ever-better, 4000kcal will soon become impossible to stomach, however. 4000kcal of carbs and low fat for years, just become obese and get metabolic syndrome.

> Calories-in-calories-out without considering the hormones

Your argument here boils down to: CICO is easier with a balanced diet. I don't think a reasonable person is going to argue against that.

> after a few weeks of keto-adaptation? They'd be a tad little bit fatter than they'd like

Honestly, if they could stomach it, they'd balloon up just as much as its opposite. Keto-adaptation doesn't change how your body processes fat, it just does a better job of not making a person feel ill when eating more fat in their diet.

> I don't think a reasonable person is going to argue against that.

You'd be surprised.

Can confirm. Did a year long dirty-bulk on a ketogenic diet while lifting heavy weights, got fat (and didn't really put on that much extra muscle either)...

What was your daily diet like?

Lots of eggs, bacon, beef, cheese, 35% cream and peanut butter.

Eating 4000 calories of anything will make you fat.

Have fun eating 4000 calories of carrots, cabbage, broccoli.. even eating brown rice is hard! Carrots have about 200 calories per pound, so we are talking about 20 pounds of carrots per day. Brown rice (cooked) has about 200 calories per cup, so again, 20 cups of brown rice?

Meanwhile a cup of vegetable oil has about 1900 calories.

The 7.4oz bowl of organic brown rice on the desk in front of me has 310 calories. It's roughly a cup by volume as well. I could easily eat 15 of them over the course of a day.

Eat (drink) 4000 calories of gasoline. wont make you fat. point is: only calories you can convert into "human fat" will make you fatter. that process can not happen without certain chemicals (hormones) in your body, like insulin mentioned above. it's not as straightforward as that which was op's point.

Are your confusing nutritional calories with physics calories? When people talk about diet, of course they are talking about calories obtained from digestion, not combustion engines.

Energy is energy, a calorie is a calorie in gasoline, food or electricity. However when talking about nutrition labels, those are generally an estimate of calories potentially extracted by humans (which I think is what you mean with nutritional calories). I'm not confusing anything. But some people seem convinced that the car analogy is exactly how the human body works - you put food into your mouth and it gets "burned" by exercise or stored (calories in, calories out) and no amount of evidence or science seems to convince them otherwise.

Not if you burn those same 4000 calories a day.

Unless you're Micheal Jai White[0] or Dwayne Johnson[1], you won't burn 4000 extra (kilo)calories a day.

[0] https://www.youtube.com/watch?v=fylDp1VtZbA&t=2m30s

[1] http://www.muscleandfitness.com/nutrition/meal-plans/smell-w...

My running app estimates I burned a bit over 4000 calories in the marathon I ran last weekend!

Though clearly this is an exceptional event, not something I could do even semi-regularly.