Weight loss is a simple energy balance equation and the types of food consumed are irrelevant to losing weight. Fewer calories consumed than burned results in weight loss. The opposite results in weight gain.
Period.
While some food types help with insulin response based on the glycemic index and can help with managing blood sugar levels in diabetic people, they do not change the weight gain/loss equation.
Folks should be aware that losing just 3% of body weight in a month results in an 18% reduction in metabolism. Multiple clinical studies have proven it. The weight loss should be no more than 1% per month to maintain metabolic stability.
The people on “The Biggest Loser” have been determined to have reduced their metabolism by 40-60%. That means their bodies are cutting the caloric burn in half to preserve the fat reserve. The body is fighting back.
You didn’t gain the weight in a short period and it is unreasonable to believe you can lose it it a short period without the body fighting it. It has become slowly conditioned to its current state and needs to be gently coaxed out of it to keep it from fighting the change.
How can I be sure? I have lost 34 lbs in 12 months using the 1% rule and have no measurable change in metabolism. My wife has lost 20 lbs in 22 months using the same rule and also has no measurable change in metabolism.