T Nation

How Long for the Body to Create Fat?

If I have a big cheat meal that exceeds my caloric needs for the day, how long before those calories appear as fat on my body? Just curious. Is it a matter of hours? Days?

I don’t think weight gain is a good indicator, because of water retention. I lost 7 pounds between Monday and Wednesday this week, nearly all of it in water weight.

Here’s the best info I could find from searching the web. It varies according to metabolism, age, food GI, etc. but overall looks like it is 10-12 hours for conversion to fat:

Matter of several minutes to several hours usually depending on what you eat or drink. Drinking fruit juice for example will obviously get absorbed much quicker than eating cottage cheese. The body gets the majority of the calories from food relatively quick and insulin does it thing sending to brain, and muscles, or storing as fat.

If you have a huge surplus of calories from a cheat meal or a cheat day the body may not digest and absorb all of the calories.

Short term weight gain is not the best indicator as stool and water weight can vary by several pounds on any given day and may have no correlation to lean body mass changes.

I knew about time for digestion, but was curious how long it took nutrients to be converted to fat once in the bloodstream. Apparently, it is very fast since the quote discusses only the time it takes to digest the food.