Why is it, that you can eat a 2,000 calorie meal, and in theory, you shouldn’t need calories again until the next day, but you can be hungry again 6-8 hours after you finish eating? Is your body just not capable of actually processing that many calories?

Question

I think the title kind of says it all, but I watched a video of someone eating a 2.1k calorie burger, and his friend said, good now you won’t need to eat for 24 hours and they laughed, then I thought, ” wait why is it that you would be hungry again after 6-8 or so hours, is our body that inefficient with those calories? Does this mean that when you eat over a certain limit of calories you body just puts the rest into waste and some into fat? How does it work?

Update: Wow thanks for all the upvotes, awards, and comments. I really appreciate all the new information and help on this topic.

In: Biology

Answer 1

Hunger is driven from hormones and Pavlov’s conditioning(sight – sizzling fats meat on a grill/smell – kfc smell /time – your usual meal times/place – favorite bar/cinema)

Energy/fat Storage is driven largely by the insulin hormone.
If you eat and insulin spikes, your body will attempt to store.

If you eat and there is little/no insulin, your body doesn’t store.

So if you don’t eat for a long enough time you can recondition some of your hunger signals.

Think of your body like a hybrid car that can run on two primary fuels.
1) The common glycogen (produced from carbohydrate and gluconeogenesis).
2) ketones (produced from burning fat dietary or stored)

If you eat enough carbohydrates, your body produces glycogen and fuels your body that way. Carbohydrates trigger insulin to be produced in the pancreas so you start storing away some of that energy.

If you don’t eat carbohydrates, your body is forced to switch to ketones.

If you don’t eat for a long enough time 48hours or so.

The glycogen within your body (liver) is reduced enough that you’re in ketosis (burning ketones instead of glycogen). Then there is very little insulin and glycogen in your system. Thereby burning/consuming fat (dietary or stored) to produce energy in the form of ketones.

This is why diabetic type 1 diabetics (can’t produce insulin) need insulin to survive and that if they don’t have exogenous insulin injected they’ll waste away into a skeleton no matter how much they eat.

This is also why fasting and the ketogenic diet (focusing on no/very low carb) works.

This also means you could eat a lot of calories by simply eating pork bellies and fatty salmon without really storing much(if you have a very low insulin environment.).

So calories don’t really count it’s the body’s insulin response that governs fat/energy storage.