The most common approach to calories during weight management is guessing. Most people eat less than usual, assume they are in a deficit, and wait for results. The problem is that calorie needs vary significantly by body weight, height, age, and activity level. Two people of the same gender and approximate age can have daily energy needs that differ by 500 calories or more. Understanding how to calculate a realistic calorie target, and why that target changes as weight falls, is one of the most practically useful decisions you can make before starting a programme.
Key Takeaway
A calorie deficit is the non-negotiable foundation of fat loss: the body must take in fewer calories than it expends. The appropriate daily deficit for most adults is 300 to 500 calories below Total Daily Energy Expenditure (TDEE). For a moderately active Indian adult in the 60 to 85kg range, TDEE typically falls between 1,800 and 2,600 calories depending on gender, height, age, and activity level. A 400 to 500 calorie daily deficit produces approximately 0.5kg of weight loss per week, the rate most consistently associated with fat loss while preserving lean muscle. Going below 1,200 calories per day for women or 1,400 calories per day for men risks meaningful muscle loss, micronutrient deficiency, and metabolic adaptation that makes the programme increasingly difficult to sustain. TDEE must be recalculated as weight falls: the same target that created a 500 calorie deficit at 90kg may create only a 200 calorie deficit at 75kg, because a lighter body burns fewer calories at rest.
What a Calorie Deficit Actually Is
A calorie is a unit of energy. The body uses calories continuously: for breathing, circulation, digestion, movement, temperature regulation, and every other physiological function. When calorie intake equals expenditure, weight stays stable. When intake exceeds expenditure, the surplus is stored, primarily as fat. When intake falls below expenditure, the body draws on stored energy to compensate.
Fat is the body's primary long-term energy reserve. Approximately 7,700 calories of cumulative deficit are required to lose one kilogram of stored fat. A daily deficit of 500 calories therefore produces roughly one gram of fat loss per day, or approximately 0.5kg per week. This is the theoretical figure. In practice, early weight loss is faster because the body also sheds water and depletes glycogen stores alongside fat. When those losses stabilise, the rate reflects actual fat reduction.
The deficit does not need to be identical every day. What matters is the weekly total. A person eating 400 calories below TDEE on five days and at maintenance on two days still produces a meaningful weekly deficit. Flexibility across the week is more sustainable for most people than a rigid daily target.
How to Calculate Your TDEE
TDEE has two components. The first is Basal Metabolic Rate (BMR): the calories the body burns at complete rest, just to maintain basic functions. BMR is determined primarily by body weight, height, age, and gender. The Mifflin-St Jeor equation is the most validated method for estimating it:
For men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
For women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
The second component is the activity multiplier: how much additional energy is burned through movement across the day. Sedentary individuals (desk work, minimal deliberate movement) multiply BMR by 1.2. Lightly active individuals (walking, light exercise 1 to 3 days per week) multiply by 1.375. Moderately active individuals (exercise 3 to 5 days per week) multiply by 1.55. Very active individuals (daily exercise or physically demanding work) multiply by 1.725.
The result is TDEE: the daily intake at which your weight stays stable. To lose weight, eat below this number by 300 to 500 calories.
What Size of Deficit to Aim For
A deficit of 300 to 500 calories per day is the range most consistently associated with sustainable fat loss while preserving lean mass (PMID 40445127). Larger deficits produce faster weight loss on the scale, but a meaningful fraction of the additional loss comes from lean tissue rather than fat, which reduces resting metabolic rate and increases the risk of regaining weight once the programme ends.
A deficit that produces 0.4 to 0.6kg of loss per week is appropriate for most people on a structured programme. Faster is not better if the cost is muscle loss. Slower is not a failure if the deficit is sustainable and protein targets are being met consistently.
As a practical starting point: if your TDEE is 2,000 calories, a daily intake of 1,500 to 1,700 calories creates a 300 to 500 calorie deficit. This is enough to produce steady progress while maintaining the food volume needed to hit protein and fibre targets. For a breakdown of what those calories should consist of: Macronutrients During Weight Management: Protein, Carbs, and Fat Explained.
What Happens When You Go Too Low
Very low calorie intakes, below 1,200 calories per day for women or 1,400 for men, create problems that compound over time.
Metabolic adaptation: The body reduces discretionary energy expenditure to compensate for significant restriction. Non-exercise movement decreases, thermogenesis slows, and the metabolic cost of digestion falls. A deficit that was 800 calories on paper becomes 400 to 500 calories in practice as the body adjusts. This is not a failure of willpower. It is a biological response to perceived energy scarcity.
Muscle loss: Very low intake makes it nearly impossible to reach protein targets. Protein requires calories to deliver. If total intake is very low, even a protein-first eating approach cannot supply the 1.2 to 1.6 grams per kilogram of body weight needed to protect lean mass during a deficit. The result is a higher fraction of weight loss coming from muscle rather than fat. For more on protecting lean mass: How to Support Lean Mass During a Calorie Deficit.
Micronutrient gaps: Adequate micronutrient intake from food requires adequate food volume. Very low calorie intakes make covering essential vitamins and minerals through food alone extremely difficult. For a breakdown of the most common gaps: Nutrient Gaps During Weight Loss: What Most People Miss.
Why Your Target Changes As You Lose Weight
BMR is calculated from body weight. As body weight falls, BMR falls with it. A person who started at 90kg with a TDEE of 2,300 calories and has now reached 75kg will have a TDEE closer to 2,050 calories. If they continue eating the same 1,800 calories they were eating at 90kg, their effective deficit is now 250 calories instead of 500, roughly half the original.
This is one of the most common reasons progress stalls during a well-structured programme without any apparent change in behaviour. The programme has not stopped working. The calorie arithmetic has shifted because the body has changed.
Recalculate TDEE every 5 to 8 kilograms of weight lost, and adjust the daily target downward to restore the deficit to the 300 to 500 calorie range. For a full guide on what to do when loss stalls: How to Break Through a Weight Loss Plateau.
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| Activity Level | Description | Male TDEE (70kg, 170cm, 35y) | Female TDEE (60kg, 160cm, 35y) | Suggested Calorie Target |
|---|---|---|---|---|
| Sedentary | Desk work, minimal movement outside of work | ~1,910 kcal | ~1,520 kcal | M: 1,400–1,550 | F: 1,200 (floor applies) |
| Lightly active | Walking, light exercise 1–3 days per week | ~2,190 kcal | ~1,740 kcal | M: 1,700–1,850 | F: 1,280–1,400 |
| Moderately active | Exercise 3–5 days per week, moderate intensity | ~2,470 kcal | ~1,960 kcal | M: 1,950–2,100 | F: 1,500–1,620 |
| Very active | Daily training or physically demanding job | ~2,750 kcal | ~2,180 kcal | M: 2,250–2,400 | F: 1,720–1,850 |
Frequently Asked Questions
How many calories should I eat to lose 1kg per week?
Losing 1kg of fat per week requires a cumulative deficit of approximately 7,700 calories, which means a daily deficit of around 1,100 calories. For most people, this requires eating below 1,200 to 1,400 calories per day, which makes it very difficult to meet protein targets and risks significant muscle loss. A more sustainable target is 0.5kg per week, requiring a daily deficit of approximately 550 calories. This can be achieved within a calorie range that still supports adequate protein, fibre, and micronutrient intake. Slower, steady loss with lean mass preserved produces better long-term outcomes than fast loss with muscle included.
Should I eat the same number of calories every day?
Not necessarily. Most people find it more sustainable to manage a weekly calorie total rather than a rigid daily target. Eating 400 calories below TDEE on five days and at maintenance on two days still creates a meaningful weekly deficit. The most common mistake is being very disciplined on weekdays but consistently exceeding the target on weekends by enough to eliminate the deficit entirely. A rough awareness of the weekly total, rather than perfect daily tracking, is sufficient for most people to make consistent progress.
Is 1,200 calories per day too low?
For most adults, 1,200 calories is a practical minimum rather than an appropriate target. At this intake, meeting protein requirements (1.2 to 1.6g per kg body weight), eating sufficient fibre, and covering micronutrients through food alone is extremely difficult. For a 70kg person, protein at 1.4g/kg is 98 grams per day, representing approximately 400 calories from protein alone. That leaves only 800 calories for everything else. Unless under direct clinical supervision with nutritional support, most adults should aim for an intake that allows protein targets to be comfortably met within the calorie budget.
How do I estimate calories on an Indian diet?
The most practical approach is to track the three highest-calorie components of each meal: the protein source, the grain portion, and any added fats. A typical Indian plate of dal (150 kcal), two whole wheat rotis (180 kcal), a teaspoon of ghee (40 kcal), and sabzi (60 kcal) totals approximately 430 kcal. Applying this logic across three meals gives a reasonable estimate without tracking every ingredient precisely. Portion sizes of grains, ghee, and oil are where most untracked calories accumulate, so consistency with those three inputs is usually enough for meaningful calorie awareness.
Why have I stopped losing weight even though I haven't changed my diet?
As body weight falls, TDEE falls with it. The deficit that produced consistent loss at 90kg may become negligible at 75kg because a lighter body burns fewer calories at rest. If you have been eating the same amount for several months without adjusting for your new weight, your effective deficit may now be close to zero. Recalculate TDEE at your current weight using the Mifflin-St Jeor formula and adjust your daily intake target downward by 100 to 200 calories to restore a meaningful deficit. This is a normal and expected adjustment, not a sign the programme has failed.
References
- Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989–1002. PMID 33567185
- Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity. Obesity (Silver Spring). 2025;33(8):1475–1503. PMID 40445127
LeanOn products are health supplements, not drugs. They are designed to support nutritional needs during structured weight management. Consult your healthcare provider before use.