Besides the well-known reason – you eat more calories than you spend, there are quite a few reasons to why you may not be losing the weight.
During stressful times our bodies produce more of a stress hormone – cortisol. Chronically high levels of which lead to a lot of dis-balance. But even relatively short spikes of cortisol will affect water balance in the body. Higher cortisol levels = water retention.
2. Increase in carbs
Each gram of carbohydrate attracts up to 3g of water. So if one day you ate more carbs than usual, you sure will see it on the scale.
3. Water intake
Our bodies regulate water and sodium balance by different mechanisms. Diuretic hormone vasopressin and anti-diuretic hormone ADH are largely responsible for the water balance in your body. Every time you change your water intake your body needs time to adjust. Let’s say you drink 1 gallon of water a day on regular basis. If on one of the days you drink 2 or 3 gallons you will notice weight gain next morning because your body didn’t have time to catch up with the new water intake amount.
4. Salt intake
Similar to the water balance, the amount of salt in bodily fluids is also tightly regulated. Variation in salt intake causes cells to either shrink or swell by attracting more or less water.
Food in restaurants tends to have more flavor and salt than the one we eat at home. So often, even if you eating out meal was a good healthy option, you will see an increase in your body weight the next morning.
5. GI problems
Any kind of GI problems, like diarrhea or constipation, will cause weight fluctuations due to the constant salt and water balance change.
6. Weighing at different times/conditions
This one seems obvious, but yet… Weighing yourself first thing in the morning will always yell different results from the weight you see during the day or in the evening due to the food and fluid intake. To get the most accurate measurement, ensure you are weighing yourself in similar conditions every time.
There are a lot more reasons to why your weight can fluctuate on a day to day basis and that is exactly why weight should be used only as a tool. For the more accurate progress measurement include circumference of your waist, navel, and hips. Measuring once a week or every other week will give a good idea on whether you are moving in the right direction.