Work out your calories, then your protein, carbs and fat — the actual numbers, not a guess.
Total Daily Energy Expenditure Mifflin-St Jeor
Macronutrient Targets
How It Works
BMR is the number of calories your body burns at rest, before any activity is added on.
Irish Supermarket Protein Sources
Protein per 100g, standard label figures
Protein first: 1.6–2.2g per kg of bodyweight holds muscle while you lose fat, and it keeps you fuller per calorie than either of the other two. Fat sits around 0.8–1g per kg for hormones. Carbs take whatever calories are left — they are the lever, not the enemy. Want the working shown rather than just the answer? How to calculate your macros step by step goes through it with Irish supermarket food.
No. Calories decide whether the weight moves; macros decide what you lose and how you feel doing it. Same deficit with higher protein means more of the loss comes from fat instead of muscle.
Roughly right most days beats perfect for a fortnight and then quitting. Get protein close and let the rest land where it lands.
Prefer a dedicated calorie tool? Try the TDEE calculator, or check your starting point with the body fat calculator.
About the author
Keith O’Beirne went from 90kg to 72kg around a full-time job and two kids, after paying a personal trainer to learn the basics. He is not a doctor, dietitian or coach and does not sell coaching — he writes No Nonsense Fitness to give away what he paid to learn, free, with no ads, no subscriptions and no commission on any link. Based in Dublin.
Full methodology, including how protein, fat and carb targets are set from your calories, is in our methodology page.