Why are the first pounds that you lose on a diet attributed to water loss? Why does the body start losing water with a calorie deficit?
In: Biology
Also when people talk about ‘water weight’, a lot of the time it’s actually ‘poo weight’. You start eating a lot less, there’s a lot less in the plumbing at any given time.
Those first few pounds are a lot of different things.
1. Food in your digestive tract. When you make a large calorie restriction, there’s naturally less stuff in there
1. Glycogen stored in your muscles and liver. This is the energy that gets you through your day, when you fast overnight, that your muscles use during exercise, etc. Less intake means less storage (kind of the opposite of when an athlete carb loads the day before a race).
1. Water associated with glycogen. Glycogen is is easier to burn than fat, but harder to store. Every gram of glycogen needs about 3 grams of water to surround it so it can be packed together. Less glycogen means less of that water.
1. Water retained from sodium. Many people start with a diet high in salty processed foods, which leads to water retention. Eating healthier food (and less in general) leads to less fluid retention.
That all adds up to maybe 2-3% of your gross body weight that you could loose or regain in a day or two with sudden diet changes, without actually having any impact on your amount of body fat.
Part of it is due to glycogen. Glycogen is the long-term storage for glucose and needs a lot of water to be stored. Whenever we begin a caloric deficit we burn glycogen to keep metabolic needs while we adjust. Freeing up the glycogen to burn also pulls out the water and that gets urinated out.
Latest Answers