Calorie Deficit/Surplus Calculator

ZigZag Calorie Cycling (or 'Calorie Shifting') varies your daily intake while keeping the weekly average the same. Instead of eating 1,500 calories every day, you might eat 1,200 on weekdays and 2,250 on weekends. This approach helps prevent metabolic adaptation (your body slowing down to match intake) and provides psychological breaks, making long-term diet adherence easier.

Refeed days (higher calorie days, usually high carb) boost levels of Leptin, the 'satiety hormone' that regulates metabolism. Prolonged dieting lowers leptin, signalling your body to conserve energy. A strategic refeed signals that food is available, potentially keeping your metabolic rate higher than a static linear deficit would.

A standard, sustainable deficit is 500 calories/day, leading to ~1 lb of loss per week. Beginners or those with higher body fat content can safely handle larger deficits (750-1000 cal). However, aggressive deficits (>1000 cal) increase the risk of muscle loss, nutrient deficiencies, and gallstones. Our calculator warns you if you go below safe minimums.

Yes, but it is harder. This is called 'Body Recomposition'. To achieve this, you need a smaller deficit (200-300 cal), high protein intake (0.8-1g/lb of bodyweight), and heavy resistance training. Beginners ('newbie gains') and those returning to training ('muscle memory') see the best results with recomposition.

The 5:2 diet involves eating at maintenance calories for 5 days of the week and restricting calories significantly (often to 500-600) for 2 non-consecutive days. Our calculator adapts this by ensuring your weekly average still meets your specific weight loss goal, rather than just using arbitrary numbers.

Daily weight fluctuates due to water retention, sodium intake, glycogen storage (carbs hold water), and digestion. A single heavy meal can add 2-3 lbs of temporary water/food weight. This is why weekly averages are far more accurate than daily scale readings. Do not panic over daily spikes.

TDEE stands for Total Daily Energy Expenditure. It is the total number of calories you burn in a day, including your BMR (Basal Metabolic Rate - coma calories), NEAT (movement like walking/fidgeting), EAT (Planned Exercise), and TEF (Thermic Effect of Food). To lose weight, you must eat below your TDEE.

A Calorie Surplus is needed to maximize muscle growth ('Bulking'). A mild surplus of 250-500 calories is recommended generally. Eating more than this ('Dirty Bulking') usually leads to excessive fat gain alongside muscle. Use our calculator to set a controlled surplus.

Consistently strict eating below 1200 calories (for women) or 1500 (for men) is generally not recommended without medical supervision. It can lead to 'Relative Energy Deficiency' (RED-S), causing hormonal imbalances, hair loss, loss of menstrual cycle, weakened bones, and extreme metabolic slowing.

Be cautious. Fitness trackers often overestimate calories burned by 25-50%. If you eat back all 'burned' calories, you may erase your deficit. It is safer to consider exercise as a 'bonus' burn that speeds up results, or only eat back 50% of what your tracker claims.

Plateaus happen because your TDEE drops as you lose weight (a smaller body burns less energy). To break a plateau: (1) Recalculate your TDEE with your new weight, (2) Take a 'Diet Break' at maintenance for 1-2 weeks to reset hormones, or (3) Increase your daily NEAT (steps).

Protein is the most critical macronutrient during a deficit. High protein intake (1) preserves muscle mass so you lose mostly fat, (2) keeps you fuller for longer (highest satiety), and (3) burns more calories to digest (highest Thermic Effect) than carbs or fats.

Reverse Dieting is the process of gradually increasing calorie intake after a long diet, rather than jumping straight back to high calories. This theoretically allows your metabolism to 'catch up' helping you find your new maintenance level without rapid fat regain.

For pure weight loss (calories in/out), meal timing is not very significant. You can lose weight eating 6 meals or 1 meal (Intermittent Fasting) as long as calories are equal. However, nutrient timing (protein around workouts) can help with muscle retention and performance.

Low-carb diets (like Keto) often result in rapid initial weight loss due to water shedding (glycogen depletion). Long term, studies show that if protein and calories are equal, low-carb and low-fat diets result in similar fat loss. The 'best' diet is whichever one you can stick to consistently.