When you burn fat is it the latest fat you stored from eating that gets burned or is it totally random?


When you burn fat is it the latest fat you stored from eating that gets burned or is it totally random?

In: Biology


Do i understand correctly that you’re asking if burning fats follows a “Last-in-first-out” system?

In case you haven’t gotten an answer to your question yet, OP, the short answer is its a mix of both.

Your body stores fat predominately in 2 ways. The first is in adipose tissue, or, specific cells designed to store fat. The second is fat circulating through your system, bound to fat transport proteins. Fat that is deposited in adipose is the most difficult to burn, however, fat molecules are constantly being cycled from the blood to these stores so its difficult to track which fat molecules were ingested first. The fat you most recently consumed will end up in the blood sooner than adipose storage, so the simplest answer is yes, but again due to all the processing and interchange of fat molecules, it’s not super cut and dry.

When you eat fat, you are eating another animals fat (or a plants fat) this doesn’t become your fat. You digest the fat by the action of lipase enzymes, that becomes tryglycerol and fatty acids, which becomes glycerol, which becomes pyruvate and then gluconeogenesis causes it to become glucose. This enters the blood, your blood sugar spikes.

These products are broken down by various chemical reactions in the stomach/intestines, enter the blood, when blood sugar spikes after a meal insulin release tells the body to start taking glucose from the blood – the muscles, liver and fat cells then take this from the blood and store it.

When your body uses energy during exercise, it uses the energy already in the muscles first and when the energy in the muscles depletes then that comes from the blood. Which causes the energy in the blood to drop, which then causes the release of glucagon, which has the opposite effect of insulin and pulls energy from the stores of energy in other parts of the body.

Because there are so many different metabolites, waste products, nutrients etc that come from each bit of food that you eat, I would say it’s impossible for anyone to track where a fat molecule in your body came from – so I don’t think anyone really knows the answer to your question

Well the fat burned first is actually the interest fat, then the most recent fat, and last but not least, the principle fat.



While we’re at it, can someone disprove the myth about doing crunches burning specifically belly fat?

The book, “Secret life of Fat” is a good source of info for Fat. Essentially, Adipose fat is an organ, that communicates to your brain.

Relates different body fuels as cash, checking, and long term investments.
Some are easy to burn, some take a while to liquidate.

Sorry about piggy backing off of this topic, but is there any truth to the idea that eating before bed makes you gain weight, even if your in a caloric deficit?

Hello sugar plays giant role here from what I understand and it’s not directly that fat you eat gets stored as fat in your cells. Not a nutritionist can anyone answer?