Question 1

How many calories should I eat to lose weight?

Accepted Answer

Start from your maintenance calories — the amount that holds your weight steady — and subtract a deficit. About 500 kcal/day produces roughly 0.5 kg (1 lb) of fat loss per week, the sustainable rate most guidelines recommend. The Weight Loss Calculator estimates your maintenance with the Mifflin-St Jeor equation, then subtracts the deficit for the weekly rate you choose, and warns you if the target would fall below a safe minimum (about 1,200 kcal/day for women, 1,500 for men).

Question 2

How much weight can I safely lose per week?

Accepted Answer

For most people, 0.25–1 kg (0.5–2 lb) per week is safe and sustainable — a useful ceiling is about 1% of your bodyweight per week. Heavier people can lose a little faster at first; those near their goal should aim slower to protect muscle. Losing much faster usually costs muscle and is hard to keep off, which is why crash diets rebound.

Question 3

How does the weight loss calculator work?

Accepted Answer

It uses energy balance. First it estimates the calories you burn in a day (your maintenance, or TDEE) from your height, weight, age, sex and activity. Then it applies your chosen weekly loss rate: since roughly 7,700 kcal equals 1 kg of fat, a target of 0.5 kg/week works out to a 550 kcal daily deficit, which it subtracts from maintenance to give your daily calorie target. Add a goal weight and it also estimates how many weeks the plan takes.

Question 4

What is BMI and how is it calculated?

Accepted Answer

Body Mass Index (BMI) is a numerical value derived from your weight and height. It is calculated by dividing your weight in kilograms by the square of your height in metres. It is a useful population-level screening tool but does not directly measure body fat and cannot distinguish between muscle and fat mass.

Question 5

Why does BMI sometimes incorrectly categorise athletes?

Accepted Answer

Standard BMI only factors in total body weight against height — it cannot account for body composition. Muscle tissue is denser and heavier than fat by volume. Highly trained athletes who carry significantly more lean mass than average often fall into the 'overweight' or 'obese' BMI categories despite having very low body fat.

Question 6

Is BMI a good indicator of health?

Accepted Answer

BMI is a useful screening tool, not a diagnostic one. It does not measure body fat directly or account for age, sex, bone structure, or muscle mass. Healthcare providers typically use BMI alongside other assessments — waist circumference, diet, physical activity, and blood work — to evaluate an individual's overall health risk.

Question 7

What is a healthy BMI for Asian adults, and how does the Asian BMI calculator work?

Accepted Answer

For adults of South, East, or Southeast Asian descent, the WHO 2004 Expert Consultation sets a lower healthy BMI range of 18.5–22.9, with overweight beginning at 23.0 and obesity at 27.5 — reflecting higher metabolic and type 2 diabetes risk at lower BMI values than in European populations. Turn on the Asian descent toggle in our BMI calculator to score your result against these adjusted thresholds. The cut-offs are the same for Asian men and women; there is no separate formula for females.

Question 8

What is the difference between BMR and TDEE?

Accepted Answer

Basal Metabolic Rate (BMR) is the calories your body needs for basic life-sustaining functions — breathing, circulation, cell repair — while completely at rest. Total Daily Energy Expenditure (TDEE) multiplies your BMR by an activity factor to account for daily movement, exercise, and the thermic effect of food. TDEE is the total calories you burn in a day.

Question 9

How can I get an accurate TDEE?

Accepted Answer

Our TDEE calculator uses the Mifflin-St Jeor equation — the most validated formula for modern populations — to provide a reliable daily calorie estimate. However, it remains an estimate. Individual factors such as NEAT (non-exercise activity thermogenesis), sleep quality, genetics, and metabolic adaptation can cause your actual TDEE to vary slightly from the calculated value.

Question 10

How often should I recalculate my TDEE?

Accepted Answer

Recalculate whenever you experience a significant change in body weight or activity level. A good rule of thumb: re-run the numbers after losing or gaining 5–10 lbs (2–4 kg), or if you transition between sedentary and active phases of your life.

Question 11

What is BMR (Basal Metabolic Rate)?

Accepted Answer

Your Basal Metabolic Rate is the number of calories your body burns at complete rest — breathing, circulation, organ function and temperature control. It typically accounts for 60–70% of your total daily calorie burn. Everything you do on top of that, from standing to exercise to digesting food, adds more.

Question 12

What is the difference between BMR and TDEE?

Accepted Answer

BMR is your at-rest burn; TDEE (Total Daily Energy Expenditure) is your whole-day burn once activity is included. You get TDEE by multiplying BMR by an activity factor, from about ×1.2 for a sedentary person to ×1.9 for very active. BMR is the foundation, but TDEE is the number you actually eat to — the BMR Calculator hands off to the TDEE Calculator for that step.

Question 13

Should I eat my BMR to lose weight?

Accepted Answer

No — eating only your BMR is almost always too few calories. BMR is your resting burn, not a target. To lose weight safely you start from your TDEE (BMR plus activity) and subtract a moderate deficit, keeping your intake above a safe minimum. The Weight Loss Calculator does this for you and flags a target that dips too low.

Question 14

What is the Katch-McArdle formula and when should I use it?

Accepted Answer

The Katch-McArdle formula estimates your BMR from lean body mass: BMR = 370 + 21.6 × lean mass (kg), where lean mass = weight × (1 − body fat% ÷ 100). Multiplying by an activity factor gives your TDEE. Use it when you know your body fat percentage and have a lean or muscular build — because it works from the tissue that drives metabolism, it is usually more accurate than height/weight formulas for athletes and people deep into a body-recomposition phase.

Question 15

How is Katch-McArdle different from the Mifflin-St Jeor formula?

Accepted Answer

Mifflin-St Jeor estimates BMR from age, height, weight and sex, so two people of the same stats get the same result regardless of body composition. Katch-McArdle instead uses lean body mass, so a muscular 80 kg person and a less-lean 80 kg person get different (more accurate) numbers. The trade-off: Katch-McArdle needs an accurate body fat measurement, while Mifflin-St Jeor does not. If you do not know your body fat, Mifflin-St Jeor is the safer default.

Question 16

Do I need my body fat percentage to use the Katch-McArdle calculator?

Accepted Answer

Yes — body fat percentage is the only input unique to Katch-McArdle and the formula cannot run without it. If you do not know it, estimate it with the Body Fat Percentage Calculator first (the US Navy tape-measure method needs no equipment), then return to the Katch-McArdle calculator for your BMR, TDEE and calorie targets.

Question 17

What is a reverse dieting calculator?

Accepted Answer

A reverse dieting calculator builds a week-by-week plan to gradually raise your calories from your current (post-diet) intake back up to your maintenance level, while holding protein steady to protect muscle. It estimates your maintenance calories (TDEE) using the Mifflin-St Jeor equation, then adds a small weekly increase — typically 50 to 150 kcal — so your metabolism can adapt upward with the least possible fat regain.

Question 18

How many calories should I add each week when reverse dieting?

Accepted Answer

Most people add between 50 and 150 kcal per week. A conservative pace (+50 kcal/week) is best after a long or aggressive diet; a moderate pace (+100 kcal/week) is a balanced default; an aggressive pace (+150 kcal/week) suits short cuts or experienced dieters. The extra calories are added mostly through carbohydrates, with protein kept constant.

Question 19

Will I gain weight when reverse dieting?

Accepted Answer

Expect 0.5–1 kg (1–2 lb) of scale weight in the first week or two, but this is mostly muscle glycogen and water refilling — not body fat. Adding calories gradually instead of snapping straight back to maintenance is exactly what keeps genuine fat regain to a minimum.

Question 20

How much weight can you lose with intermittent fasting?

Accepted Answer

Intermittent fasting causes weight loss only by helping you eat fewer calories overall — most people spontaneously eat 10–30% less when they shorten their eating window. For a typical adult that is roughly a 300–600 kcal daily deficit, projecting to about 0.3–0.6 kg (0.7–1.3 lb) of fat per week. The calculator estimates your own figure from your maintenance calories and chosen schedule, and shows a realistic range rather than a single optimistic number.

Question 21

Which intermittent fasting schedule is best for weight loss?

Accepted Answer

The best schedule is the one you can stick to. 16:8 (a 16-hour fast, 8-hour eating window) is the most popular and best-studied and suits most beginners. Longer windows like 18:6, 20:4 and OMAD create a bigger calorie reduction but are harder to sustain and can push intake below safe levels. 5:2 and 4:3 let you eat normally most days with two or three low-calorie fast days.

Question 22

Does this work as a water fasting weight loss calculator?

Accepted Answer

No — and that is deliberate. Prolonged water-only fasting can cause dangerous electrolyte shifts, muscle loss and refeeding problems, so it should only be done under medical supervision and is not something we project a weight-loss number for. This calculator covers time-restricted eating (16:8, OMAD, etc.) and intermittent whole-day plans (5:2, 4:3), where you still eat and the deficit is sustainable.

Question 23

Is intermittent fasting good for weight loss for women?

Accepted Answer

Yes — the mechanism is the same for everyone: fasting helps you eat fewer calories, and that deficit drives fat loss, so women lose weight on 16:8, 5:2 and similar schedules just as men do. There are a few female-specific points: some women find very long daily fasts (20:4 or OMAD) affect their energy, sleep or menstrual cycle, so gentler windows like 14:10 or 16:8 are usually a better starting point. On 5:2, the classic fast-day allowance is about 500 kcal for females (versus 600 for men) — the calculator applies that automatically, with a lower safe-intake floor of around 1,200 kcal/day. Intermittent fasting is not recommended during pregnancy or breastfeeding, or for anyone with a history of disordered eating.

Question 24

What is a zigzag calorie calculator?

Accepted Answer

A zigzag calorie calculator (also called calorie cycling) builds a 7-day plan in which your daily calories vary — higher on some days, lower on others — while the weekly average stays exactly the same as a flat plan. It estimates your maintenance calories with the Mifflin-St Jeor equation, sets a weekly average for your goal (a 500 kcal/day cut to lose, maintenance to hold, or a 300 kcal/day surplus to gain), then distributes that average across the week with a fixed high/low pattern so the seven days still average back to your target.

Question 25

Does calorie cycling help you lose weight faster?

Accepted Answer

No — calorie cycling does not create a larger weekly deficit than eating the same amount every day; the weekly average, and therefore the total deficit, is identical. What it can do is improve adherence: the higher days line up with hard training or social meals, the lower days carry the cut, and the variety helps some people avoid the burnout that derails flat diets. Better adherence is what produces better real-world results, not a metabolic trick.

Question 26

Is zigzag dieting better than eating the same calories every day?

Accepted Answer

It depends on you. Controlled studies comparing calorie cycling with continuous restriction show broadly similar fat-loss outcomes when the weekly average is matched — the deciding factor is which approach you can sustain. Zigzag dieting suits people who train hard on some days and rest on others, or who want flexibility for a weekend; if a single consistent daily number is simpler to follow, that is equally effective.

Question 27

What is a caloric deficit and how much should I aim for?

Accepted Answer

A caloric deficit occurs when you consume fewer calories than your TDEE, prompting your body to burn stored fat for energy. For sustainable weight loss, clinical guidelines recommend a moderate deficit of 300–500 kcal/day, producing approximately 0.5–1 lb (0.25–0.5 kg) of fat loss per week.

Question 28

Can large calorie deficits backfire?

Accepted Answer

Yes. Deficits exceeding 750 kcal/day carry a high risk of lean muscle loss, nutrient deficiencies, fatigue, and metabolic adaptation — where your body lowers NEAT to conserve energy, slowing fat loss — and should only be attempted under medical supervision. A moderate, sustainable deficit is clinically recommended for long-term results.

Question 29

Should I eat back calories burned from exercise?

Accepted Answer

If you accurately selected your activity level in the TDEE calculator, your exercise calories are already factored into your daily target. Eating back exercise calories on top of that often leads to double-counting, which can unintentionally erase your deficit.

Question 30

What are macronutrients and why do they matter?

Accepted Answer

Macronutrients are the three main nutrient categories that provide energy: proteins, carbohydrates, and fats. Each plays a distinct role — protein repairs and preserves muscle tissue, fats support hormone regulation, and carbohydrates provide readily available energy. Getting the right balance at your calorie target is what separates fat loss from muscle loss.

Question 31

What is the best macro split for weight loss?

Accepted Answer

There is no universal 'best' split, but a common starting point is 30% protein, 40% carbohydrates, and 30% fats. Higher protein ratios (up to 40%) are frequently recommended during a calorie deficit because protein preserves lean muscle mass and significantly increases satiety. Use the Macro Calculator to personalise this to your body weight.

Question 32

Do macros matter more than total calories for weight loss?

Accepted Answer

For scale weight loss, total calorie balance (calories in vs. calories out) is the primary driver. However, macros — especially protein — are critical for body composition: ensuring you lose fat rather than muscle. A high-protein deficit tends to produce better visual and health outcomes than a calorie-matched low-protein one.

Question 33

How much protein do I need per day?

Accepted Answer

It depends on your goal and how active you are. As a guide, 1.2–1.6 g of protein per kg of body weight covers maintenance, 1.8–2.4 g/kg supports fat loss, and 1.6–2.2 g/kg suits building muscle. For an 80 kg adult that is roughly 112 g to maintain, 168 g for fat loss, and 152 g to build muscle. The Protein Intake Calculator turns the band for your goal into a low–high range plus a recommended midpoint, and nudges it up the more you train.

Question 34

Should I base protein on body weight or lean body mass?

Accepted Answer

If you know your body fat percentage, lean body mass is more accurate, because fat tissue does not need feeding with protein. The lean-mass method uses 2.3–3.1 g per kg of lean mass. If you do not know your body fat, the body-weight method is a reliable shortcut — enter a measured body fat % to switch to the sharper lean-mass figure.

Question 35

How much protein should I eat to lose weight?

Accepted Answer

In a calorie deficit, aim for the fat-loss band of 1.8–2.4 g per kg of body weight. Higher protein while dieting preserves lean muscle, has the highest thermic effect of any macro, and is the most filling — all of which make fat loss easier and protect your results, which is why the fat-loss band sits well above the general 0.8 g/kg RDA.

Question 36

How much water should I drink a day?

Accepted Answer

A practical starting point is about 35 ml of water per kilogram of body weight — roughly 2.4 litres (around 10 glasses) for a 70 kg adult — then add about 350 ml for every 30 minutes of exercise and 10% more in a hot climate. The Water Intake Calculator works this out for you and shows the result in litres, glasses and bottles with a sensible range, rather than the flat 'drink 2 litres' rule that ignores your size and activity.

Question 37

Does drinking water help with weight loss?

Accepted Answer

Indirectly, yes. Water has zero calories, and a glass before a meal increases fullness so you tend to eat a little less. Thirst is also easy to mistake for hunger, so staying hydrated curbs unnecessary snacking, and swapping sugary drinks for water removes easy-to-over-consume liquid calories. Water is not a fat-burner on its own — it supports appetite control and replaces higher-calorie drinks.

Question 38

Do I need more water when I exercise or it's hot?

Accepted Answer

Yes to both. You lose fluid through sweat, so the calculator adds about 350 ml of water for every 30 minutes of exercise, and lifts your whole daily total by 10% in a hot or humid climate. For long or intense sessions, especially in the heat, you may also need electrolytes (sodium) alongside the extra water. Urine colour is the simplest real-time check — pale straw is the target.

Question 39

How is ideal weight calculated?

Accepted Answer

Ideal weight is estimated using validated formulas — Devine, Robinson, Miller, and Hamwi — that calculate a clinically healthy weight range based on height and sex. Our calculator presents the average of all four to give a realistic, balanced target rather than a single arbitrary number.

Question 40

Is the ideal weight the same for everyone of the same height?

Accepted Answer

No. The formulas provide a general target based on height and sex, but don't account for frame size, muscle mass, age, or genetics. Two people of identical height can have different healthy weights. The calculated ideal weight is a useful guideline — not an absolute prescription.

Question 41

What is the Devine formula and how is it calculated?

Accepted Answer

The Devine formula (1974) is the clinical standard for estimating ideal body weight, originally created for drug dosing. It uses a base weight at 5 ft (60 in) plus a fixed increment per inch above that: men = 50 kg + 2.3 kg per inch over 5 ft; women = 45.5 kg + 2.3 kg per inch over 5 ft. For example, a 5 ft 10 in man = 50 + (10 × 2.3) = 73 kg. Our ideal weight calculator runs the Devine formula and averages it with the Robinson, Miller, and Hamwi formulas for a balanced target.

Question 42

How is body fat percentage calculated without calipers?

Accepted Answer

The U.S. Navy Body Fat Formula estimates body fat from circumference measurements of your neck, waist, and (for women) hips, combined with height. It requires no equipment beyond a tape measure. While not as precise as DEXA scanning or hydrostatic weighing, it provides a reasonably accurate estimate for tracking trends over time.

Question 43

What is a healthy body fat percentage?

Accepted Answer

Healthy ranges vary by sex and age. Using the ACE classification this calculator applies, the 'Acceptable' (healthy) range for adult men is 18–24%; for adult women, 25–31%. Fitness-level ranges are 14–17% for men and 21–24% for women. Essential fat (minimum for survival) is approximately 2–5% for men and 10–13% for women.

Question 44

What is lean body mass and how is it calculated?

Accepted Answer

Lean body mass (LBM) is everything in your body that is not fat — muscle, bone, organs, connective tissue and water — so total weight = lean body mass + fat mass. If you know your body fat percentage, LBM is exact: weight × (1 − body fat% ÷ 100). Without a body fat measurement, the Lean Body Mass Calculator estimates it from height, weight and sex using the Boer (1984), James (1976) and Hume (1966) formulas, and shows their average.

Question 45

Why does lean body mass matter for weight loss?

Accepted Answer

Lean mass is metabolically active tissue, so it largely determines your resting metabolic rate — the Katch-McArdle formula calculates calorie needs directly from it. During a diet the goal is to lose fat while preserving lean mass; losing muscle lowers your metabolism. Adequate protein and resistance training protect lean mass in a calorie deficit, which is why tracking LBM gives a truer picture of progress than scale weight alone.

Question 46

What is weight loss percentage and why is it more useful than pounds lost?

Accepted Answer

Weight loss percentage expresses your loss as a proportion of your starting body weight — e.g. losing 10 lbs from 200 lbs is a 5% loss. This metric is clinically more meaningful than absolute pounds because health outcomes (cholesterol, blood pressure, insulin sensitivity) are tied to percentage thresholds rather than raw scale numbers.

Question 47

What are the clinical milestone percentages?

Accepted Answer

A 5% loss from starting weight produces measurable improvements in metabolic health markers — blood pressure, triglycerides, and fasting glucose. A 10% loss is associated with significant reductions in cardiovascular disease risk. A 15–20% loss is typically where visible body composition changes become most pronounced.

Question 48

How do I track my rate of loss over time?

Accepted Answer

Enter your starting weight and your current weight on different dates to calculate both the total percentage lost and your weekly rate of loss. A healthy rate is 0.5–1.0% of starting body weight per week — faster rates increase the risk of muscle loss and metabolic adaptation.

Question 49

How is my goal weight date calculated?

Accepted Answer

The calculator uses the energy balance model: it multiplies your weight to lose by 7,700 kcal/kg (or 3,500 kcal/lb) to find the total calorie deficit required, then divides by your chosen daily deficit to arrive at the number of days to your goal. Your TDEE — calculated from height, weight, age, sex, and activity level using the Mifflin-St Jeor equation — is the baseline.

Question 50

How fast is it safe to lose weight?

Accepted Answer

Clinical guidelines recommend a maximum of 0.5–1.0 kg (1–2 lbs) per week for sustainable fat loss. Faster rates increase the risk of lean muscle loss, gallstones, nutritional deficiencies, and metabolic adaptation. The calculator flags any target that requires a daily deficit above 1,000 kcal.

Question 51

Should I recalculate my plan as I lose weight?

Accepted Answer

Yes — every 5–10 lbs (2–4 kg) lost. As your body mass decreases, your TDEE drops, meaning the same calorie intake produces a smaller effective deficit. Recalculating regularly prevents the gradual plateau that occurs when you apply a static target to a lighter body.

Question 52

How does the calculator estimate calories burned walking?

Accepted Answer

The calculator uses the MET (Metabolic Equivalent of Task) formula: Calories = MET × body weight (kg) × time (hours). Each walking pace has a validated MET value from the Compendium of Physical Activities — from 2.5 for leisurely walking up to 11.0 for race walking. Heavier people burn more calories per session because energy cost scales with body mass.

Question 53

How does walking pace affect calorie burn?

Accepted Answer

Pace has a strong effect on energy expenditure: moving from leisurely (2.5 MET) to brisk walking (5.0 MET) doubles your calorie burn per minute. For maximum calorie burn without running, brisk or power walking — where you break a sweat — is far more efficient than slow strolling.

Question 54

Can walking alone produce meaningful weight loss?

Accepted Answer

Yes, when combined with a modest dietary adjustment. A 45-minute brisk walk at 70 kg burns ~350–400 kcal. Adding a 300 kcal daily food reduction creates a ~650–700 kcal total daily deficit — enough to lose approximately 0.6–0.7 lbs per week. Walking alone, without dietary change, typically produces 0.3–0.5 lbs/week.

Question 55

How many steps does it take to burn 500 calories?

Accepted Answer

It depends on your body weight and height. For an average 70 kg (154 lb) person of average height (170 cm), roughly 19,000–20,000 steps burns approximately 490–510 calories above resting metabolism at moderate pace. Heavier and taller individuals burn more per step because both factors increase the total distance covered.

Question 56

Does 10,000 steps a day help you lose weight?

Accepted Answer

10,000 steps a day creates a meaningful calorie deficit for most people — typically 220–400 kcal above resting — which contributes to 0.5–1 lb of weekly fat loss when combined with a moderate dietary deficit. The original 10,000-step target came from a 1960s Japanese marketing campaign, not clinical research, but subsequent studies confirm its health value.

Question 57

What is step length and how does it affect the calculation?

Accepted Answer

Step length is the distance covered per foot placement — typically 41–45% of your height (a full stride is two steps, ≈ 83% of height). Taller people cover more ground per step, affecting both total distance and calorie burn per 1,000 steps. Our calculator estimates your step length from height (×0.414); you can improve accuracy by measuring your actual step length over a known distance.

Question 58

How does the Calories Burned Calculator estimate my burn?

Accepted Answer

It uses each activity's MET value (metabolic equivalent of task) in the formula Calories = MET × body weight (kg) × time (hours) × 1.05. MET values come from the Ainsworth Compendium of Physical Activities — for example casual walking is 2.8 MET, running at 6 mph is 9.8 MET, and the Stairmaster is about 9 MET. Because your weight is in the equation, a heavier body burns more for the identical workout. You can estimate by activity and time, or switch to 'By steps' mode to work straight from a step count.

Question 59

How many calories does weightlifting or the Stairmaster burn?

Accepted Answer

For a 70 kg (154 lb) adult over 30 minutes: light/moderate weightlifting (3.5 MET) burns about 130 kcal, vigorous lifting (6 MET) about 220 kcal, and the Stairmaster (9 MET) roughly 330 kcal. Treadmill running at 6 mph burns about 360 kcal over the same 30 minutes. Heavier people and higher intensities both push these numbers up — enter your own weight, activity and time for a personalised figure.

Question 60

How many calories does 10,000 steps burn?

Accepted Answer

For most people 10,000 steps burns roughly 300–500 kcal, depending on body weight and walking pace — about 400 kcal for a 70 kg walker at an average pace. Use the calculator's 'By steps' mode and pick your pace (casual, average, brisk or power walk) for a number matched to you. To turn daily steps into a weekly fat-loss projection, use the Daily Steps Calculator.

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