A. Damaging their metabolism.
Let me explain a little about metabolism. You need a certain amount of calories a day for your body to survive 24 hours and all your body's systems to function to the best of their ability. Add onto this the calories you need for your level of activity. Say, for example, Mary needs 1700 calories, this is her BMR (Basal Metabolic Rate) then another 800 for activity levels. Mary would need to eat 2500 calories to maintain her weight.
Let’s say Mary is eating away at 3000 calories and isn’t happy with her weight. She decides today is the day the diet and training starts. She drops down to the 1200-calories-a-day-chicken-and-lettuce diet and starts walking every day. She might see 7lbs down on the scale the first week and be delighted (and hungry!) so she keeps going. This 7lbs might be partly body fat but it will also be muscle tissue and water loss. The body will start to enter “survival mode” to cope with the minimal calories and will start to adapt. Her BMR is starting to lower. As a result, Mary might lose 4lbs the second week, and 0lbs the third week. This is because her body has adapted to surviving on 1200 calories and the only way to see the weight go down further would be to drop calories even further. Mary gets frustrated, quits her diet, and goes back to eating 3000 calories. Her body has adapted to a BMR of 1200 calories so she will gain body fat even faster and it will usually go on to the abdominal area.
SO, what I have done is focus on building my BMR up as high as possible. This means I can now eat anywhere between 2-3,000 calories a day and maintain. If you want to look "toned" you have to have muscle. “Abs” are muscles and need fuel to grow (along with training of course). The more muscle you have, the higher your BMR is.
To sum it up, picture a fire in your belly and if you keep feeding it a lot of the right fuel it will be a roaring flame that you can keep throwing food into to be burnt away.
The problem is that this is a long process and everyone wants results asap. I urge people to trust the process as it feels so wrong for a lot of people - (“What do you mean I need to eat a lot more to get leaner?”)
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