Watch your weight
Carrying extra weight is linked to more DNA damage and higher cancer rates in BRCA carriers.[1]Weill Cornell Medicine: obesity may exacerbate breast cancer risk in BRCA carriers (DNA damage findings) Keeping your weight steady through adulthood, rather than gaining, is the main lever. A few things that actually make that sustainable.
Build meals around protein first
Protein is the most filling macronutrient per calorie, and higher-protein diets consistently show better fat loss with more muscle preserved compared to lower-protein diets at the same calorie deficit.[2]Protein intake, satiety, and weight management (American Journal of Clinical Nutrition) Decide what protein you're eating first, then build the rest of the plate around it.
Fix your sleep before you fix your diet
Short sleep shifts your hunger hormones against you: lower leptin (which signals fullness), higher ghrelin (which drives hunger), and a measurable link to higher body weight.[3]Short sleep duration linked to reduced leptin, elevated ghrelin, higher BMI A consistent 7 to 8 hours does more for appetite control than most people expect from a diet change alone.
Lift, don't just diet
A calorie deficit without resistance training tends to burn muscle along with fat. Keeping 2 to 3 strength sessions a week while losing weight is what actually preserves the muscle, which is also what keeps your metabolism from slowing down as much as it otherwise would.
Aim for steady, not fast
Very-low-calorie crash diets are hard to sustain and tend to come back, often with interest. A moderate, boring deficit you can actually stick to for months beats an aggressive one you can only hold for weeks.
This page is general information, not medical advice.