Is it just fat that you are losing when you lose weight?

The term “weight loss” can be misleading.  If you’re thinking about losing weight, what you probably mean is that you want to lose unwanted excess body fat.

Most people tend to use scales to measure their weight, but the truth is that scales don’t tell you what you’re losing!

Your total body weight includes the weight of your muscles, fat, bone tissue, internal organs, and water.  So, when you lose weight, what are you actually losing?  Is it all fat, or are there other things being lost as well?

For example, many people on a 4 week calorie restricted diet, the ratio of fat, water and protein being lost can change on a weekly basis and may typically look something like this:

Week 1                                 Weeks 2 – 3                              Week 4
Fat = 25%                              Fat = 70%                                  Fat = 85%
Protein = 5%                         Protein = 10%                           Protein = 15%
Water = 70%                         Water = 20%

Whatever diet or weight (fat) loss programme you chose should, one of it’s main aims should be to change your body composition.

Body composition simply means how much fat you have compared to your lean body weight (like muscle, bone, internal organs etc).  To get a better body composition, you should aim to lose excess fat while maintaining or increasing your lean body weight (e.g. muscle mass).

Good weight loss =  Mostly fat loss + little or no muscle loss + little water loss

Bad weight loss =  Water loss + some muscle loss + some fat loss

Losing muscle reduces your metabolic rate, meaning that any extra calories which are no longer needed (due to losing some muscle), will be stored as fat and could make you gain weight even faster.

Having more muscle mass increases your metabolism, meaning you burn off more calories while making it easier to lose fat and prevent fat gain.