Here is the secret to how I lost 70 lbs on a starch based, oil-free diet with the addition of fruits and vegetables. This is the diet that Dr. McDougall recommends. No deprivation, no calorie counting, no restricting my food intake or trying to out-willpower my hunger drive, and no exercise.
The secret is calorie density. This is simply the concentration of calories per pound of food, and it varies depending on the food. Foods lower in calorie density include things like non-starchy fruits and vegetables, potatoes, sweet potatoes, whole grains, and legumes, and are high in fiber, water, and nutrients.
Jeff Novick has a terrific video explaining calorie density:https://www.youtube.com/watch?v=0CdwWliv7Hg&t=398s
Dr. McDougall’s website for information, guidance, a meal plan and food list for a starch based diet (also educational videos, success stories, newsletters, and scientific papers):https://www.drmcdougall.com/
Dr. McDougall’s demonstration of calorie density using glass beakers to represent the human stomach:https://www.youtube.com/watch?v=EWy459cHamw&t=12s