I know this may sound silly and some people won't even bat an eye when they are told not to look at the scale while trying to lose weight or gain some. Illogical as it may sound, this recommendation has it's reasons, which I sum in 5 points:
1) We are not made entirely of fat nor muscle
When trying to lose fat or gain muscle we tend to forget that our bodies are not entirely made of neither of those tissues. Remembering this is important because not all scale fluctuations are gonna be made by changes in our muscle or fat mass. Of course that in the long term, if you are looking to lose fat, the scale will reflect it. But you can be losing fat while the scale goes up or doesn't change at all. That's because most of the rapid changes we see on the scale are due to water fluctuations. Rapid increase in water stores (or decrease) is what makes the scale go up or down up to 2 kilograms within a day. That's one of the main reasons why people fear carbs so bad: they cause water retention, but remember: WATER IS NOT FAT!
2) There is no "ideal weight for stature":
Up to this day there still are some people that like to categorize their patients according to their weight for their stature. While this measurement can be of some aid, it is an error to try and make someone reach certain weight just for it to "adjust" to their stature or BMI. Again, this approach does not take into account the fact that our bodies are a mixture of different tissues, and just trying to reach certain weight may lead to undesired lean mass loss or even fat loss but with a low lean mass for starters. On the long run, this body composition is unhealthy.
3) The scale fluctuates a lot in short periods of time:
As I mentioned above, the majority of our scale fluctuations are due to water fluctuations. There are a lot of circumstances that can make our total body water to go up or down, and as this component is not "floating" around us, it will has it's impact on the scale. For instance: if you are undergoing a low carb diet and for some reason one day you end up eating more carbs than you were accustomed to, the scale will certainly pump. But that is just because your carbohydrates stores were half or almost empty, and eating more of them causes those store to replenish. And here is the number one carbophobia misunderstanding: in order for the body to retain glycogen (our carbs store) it needs water. Approximately in a relation 3:1 for water:carbohydrate. That means that for 1g of carb you store, your body needs 3 (sometimes more) grams of water, thus leading to a rapid weight increase if the storage of carbs gets filled in little time. This can cause a weight change in a blink of an eye, but remember: WATER IS NOT FAT!!
The only way for you to gain more fat or to stop losing it is by exceeding your energy requirements. If that doesn't happen, you can be certain that with time and patience your scale will go down, but it will has it's spikes. Try and picture it as it is was a price chart fluctuation. It will has it's ups and downs but what matter most is the tendency it is following.
