Neo Deist
Th.D. & D.Div. h.c.
Depends how one defines "diet".
Lots of studies show that a low carb eating plan with totally unrestricted calories results in weight loss.
For example: https://authoritynutrition.com/23-studies-on-low-carb-and-low-fat-diets/
The principle behind the diet is that it stabilizes blood sugar and all the hunger hormones, so it reduces appetite to normal levels, and results in moving the body towards a healthy body composition.
That is because carbs (breads) turn into sugars when being digested. Sugar is the #1 killer when it comes to gaining weight and getting fat.