Yes, calorie deficit is necessary for weight loss. But starvation mode doesn’t consume fat it just slows your metabolism so your body ends up PRESERVING the fat. binge eating is a big issue for obese ppl, but that means eating even if you aren’t hungry. you NEED to eat when your body is hungry or else you won’t lose fat just healthy muscle loss.
The thing is you see many fat people outside of food deserts and plenty of people in “food deserts” are in good shape as well. So while a food deserts can make finding healthy food more difficult I think the problem is more to do with an unwillingness to eat healthy foods, or just cut back in general.
"Starvation mode" is a colloquial term often used to describe the body's adaptive response to prolonged calorie restriction. When you drastically reduce calorie intake, the body initially uses stored glycogen and fat for energy. However, over time, it may also slow metabolism (adaptive thermogenesis) to conserve energy, which can reduce the rate of fat loss.
Really only in extreme starvation, the body breaks down muscle tissue for energy (via gluconeogenesis) to preserve vital functions, not just fat. The term "starvation mode" oversimplifies this complex process and is often misunderstood as the body completely halting fat loss, which isn't accurate.