Eat more fibre!
Bulking yourself out with more fibre makes a lot of sense when it comes to losing weight. Rather than filling yourself with stodgy carbohydrates that help increase your body fat, bulking your meals with more fibre means that your digestive health will improve, the contents of your guts move quicker (hence less absorption of fatty things) and you fill yourself up.
But people don't do this. Why? Because they are frightened of using the toilet more!
"But if I eat more fibre, I'll go to the toilet!" they complain. Like somehow, like a badly trained puppy, they will soil themselves or somehow commit some major social faux pax by defecating on the living room carpet in front of their guests.
Somehow, using the toilet one extra time a day is too inconvenient and embarrassing. Apparently, having poor bowel health, increased weight and all the associated health risks are much more convenient and less embarrassing.
Time to grow up. Eat more fibre. Lots more fibre.