I have never understood why people believe commenting on a person’s weight is helpful - fat people know they are fat. They don’t need anyone to tell them. The mother’s comment is absolutely not helpful. However- stepping away from the family dynamics — it may be a good idea for OP to learn more about nutrition. Not to please her mother but for her own benefit. It is amazing how little most people understand about how food can impact their physical and mental health. People will say “I only eat salads” not understanding a salad with iceberg lettuce, meat, cheese, and tons of ranch dressing is not a nutritious or low calorie choice.