Board Review Factoid:
Dieting to achieve weight loss is achievable for many. What defeats maintainers is the "energy gap". This is the increase in hunger and decrease in energy burn that happens after weight loss. Both factors are partially attributable to changes in hormones that cause ramped up appetite and less calorie burn. Closing this gap is the challenge of maintenance, both for scientists and for maintainers. Long term treatment to buffer these responses may be necessary. I like this quote: "The biological drive to regain lost weight can be countered with environmental, behavioral and pharmaceutical interventions."
Some of us may need all three, while others can get by with fewer. From my point of view, a diet which is higher in protein and low in carbs (not the extreme version but a livable diet) preserves calorie burning lean tissue. The breakdown of protein also costs the body more in calories. The low insulins produced allow fat to be released when needed and steer the body away from fat storage. Couple this with the high fiber in fruits and vegetables which are healthy for the GI micro biome and decrease stomach emptying time. Add daily exercise to mop up the extra calories that creep in. Now you've got something.