Calories Burned Calculator

Calories Burned Calculator: MET Method and Heart Rate Formula

TL;DR: Enter your weight, activity, and duration to calculate calories burned via the MET method (Ainsworth Compendium of Physical Activities). Or switch to the heart rate method and enter gender, age, and average heart rate for a Keytel-formula personalised estimate. Both methods output total kcal and kcal per minute.

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Table of Contents

• Two Methods, One Calculator — When to Use Each
• The MET Method: Formula and MET Value Table
• The Heart Rate Method: Keytel Formula
• MET vs Heart Rate: Accuracy Comparison
• Calories Burned Per Hour by Activity — Reference Table
• How Body Weight Changes the Result
• Six Worked Examples
• Why "Calories Burned" Numbers Are Always Estimates
• Calorie Burn and Weight Loss: What the Numbers Mean
• FAQ
• Assumptions and Notes
• Further Reading

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Two Methods, One Calculator — When to Use Each

Most calorie burn calculators offer only one method. This calculator offers two, because different situations call for different levels of precision.

The MET method (Activity type selector) uses the Metabolic Equivalent of a Task — a standardised, population-averaged measure of how much energy an activity demands relative to rest. It requires only your body weight, activity type, and duration. It is simple, fast, and appropriate when you do not have heart rate data or are estimating calorie burn across multiple activities.

The heart rate method (Keytel et al., 2005) uses your measured average heart rate during exercise, combined with your gender, age, and weight. Because heart rate correlates directly with oxygen consumption during sustained aerobic exercise, this method personalises the estimate to your individual cardiovascular response rather than a population average. It requires a heart rate monitor but produces a more accurate result for aerobic activities (running, cycling, swimming, rowing) where heart rate closely tracks metabolic demand.

Use the MET method when:

• You do not have heart rate data.
• You are estimating calorie burn for planning purposes (e.g., working out your weekly energy expenditure from your training log).
• The activity is not predominantly aerobic (e.g., weight training, yoga, stretching) — heart rate is a poor predictor of metabolic cost for resistance and low-intensity activities.

Use the heart rate method when:

• You have a heart rate monitor and know your average HR for the session.
• You want a personalised estimate for sustained aerobic exercise.
• You are tracking calorie intake vs. expenditure for weight management and need the most accurate estimate available without lab testing.

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The MET Method: Formula and MET Value Table

Formula

Calories (kcal) = MET × weight (kg) × duration (hours)

Where MET is the metabolic equivalent for the specific activity, weight is body mass in kilograms, and duration is exercise time in hours (minutes ÷ 60).

Example: 70 kg person running at moderate pace (MET 9.8) for 30 minutes Calories = 9.8 × 70 × 0.5 = 343 kcal

Calories per minute = 343 / 30 = 11.4 kcal/min

What Is a MET?

MET stands for Metabolic Equivalent of a Task. By convention, a MET of 1.0 represents the energy expenditure of an average person sitting quietly — approximately 3.5 mL of oxygen per kilogram of body mass per minute (roughly 1 kcal/kg/hour). This baseline was established from measurements on a healthy 40-year-old 70 kg male and has been used as the reference point for all subsequent MET research.

A MET of 2.0 means an activity requires twice the energy of sitting quietly. A MET of 10.0 requires ten times the resting energy — and so on linearly. This makes MET values intuitive for comparing activities: an activity with MET 8.0 burns roughly twice as many calories as one with MET 4.0 at the same duration and body weight.

MET Values by Activity (Ainsworth Compendium of Physical Activities, 2011)

Source: Ainsworth BE et al. (2011). 2011 Compendium of Physical Activities: a second update of codes and MET values. Medicine & Science in Sports & Exercise, 43(8), 1575–1581. https://doi.org/10.1080/02640410400022185

Why MET Values Vary Within an Activity

Jump rope at MET 11.0 and yoga at MET 2.5 illustrate the range, but MET also varies substantially within a single activity type based on intensity. Running, for example, spans from approximately 6.0 MET (slow jog, ~6 km/h) to 18.0+ MET (elite sprint pace). The MET values in this calculator represent a typical moderate effort for each activity. If you run faster or slower than the assumed pace, the MET method will over- or underestimate accordingly — the heart rate method adjusts for this automatically.

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The Heart Rate Method: Keytel Formula

Formula

Male:   rate (kJ/min) = −55.0969 + 0.6309 × HR + 0.1988 × weight − 0.2017 × age
Female: rate (kJ/min) = −20.4022 + 0.4472 × HR − 0.1263 × weight + 0.074 × age

Calories (kcal) = (rate / 4.184) × duration (min)

Where HR is average heart rate in beats per minute, weight is body mass in kilograms, age is in years, and 4.184 is the joule-to-calorie conversion factor (1 kcal = 4.184 kJ).

Source: Keytel LR et al. (2005). Prediction of energy expenditure from heart rate monitoring during submaximal exercise. Journal of Sports Sciences, 23(3), 289–297. https://doi.org/10.1080/02640410400022185

Worked Example — Keytel Formula

A 35-year-old male, 82 kg, runs at a moderate effort with an average heart rate of 155 bpm for 45 minutes.

rate = −55.0969 + 0.6309 × 155 + 0.1988 × 82 − 0.2017 × 35
     = −55.0969 + 97.7895 + 16.3016 − 7.0595
     = 51.935 kJ/min

Calories = (51.935 / 4.184) × 45
         = 12.41 × 45
         = 558.7 kcal

Calories per minute: 558.7 / 45 = 12.4 kcal/min

For comparison, the MET method for the same person (running, MET 9.8, 82 kg, 45 min): 9.8 × 82 × 0.75 = 603 kcal. The Keytel estimate is lower because 155 bpm reflects a somewhat sub-maximal effort for this individual — the heart rate method captures the actual physiological demand rather than assuming a fixed MET for "running."

Why Gender, Age, and Weight Are in the Keytel Formula

The Keytel formula includes gender because men and women have different cardiac output characteristics and haemoglobin concentrations, which affect the relationship between heart rate and oxygen consumption. Age is included because maximum heart rate declines with age, meaning the same absolute heart rate (e.g., 150 bpm) represents a higher percentage of maximum effort in an older person than a younger one — and therefore a different metabolic demand. Weight is included because larger bodies require more energy to move and have higher absolute oxygen consumption at equivalent heart rates.

Without these three corrections, a simple heart-rate-to-calorie formula would systematically overestimate calorie burn for older, lighter, or female exercisers and underestimate it for younger, heavier, or male exercisers.

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MET vs Heart Rate: Accuracy Comparison

Neither method produces an exact calorie count. Both are estimates derived from population-level data. Understanding the error characteristics of each helps you choose the right method and interpret the output correctly.

Key insight: The MET method's fixed assumption of effort is both its strength and its limitation. It is consistent and reproducible — running at "moderate pace" always yields the same MET regardless of who you are. The heart rate method is more accurate for an individual on a specific day but introduces new error sources: HR is elevated by heat, caffeine, stress, and under-recovery, all of which inflate the Keytel estimate even if actual energy expenditure has not changed.

For most practical purposes — estimating weekly training expenditure, comparing activities, planning a weight management strategy — the MET method is entirely adequate. Use the heart rate method when you are tracking intake vs. expenditure with care and have a reliable, chest-strap HR monitor producing consistent readings.

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Calories Burned Per Hour by Activity — Reference Table

The following table shows calories burned per hour for three representative body weights using the MET formula. These are illustrative benchmarks — actual values depend on individual effort, fitness level, and technique.

Calories burned per hour (kcal/hour) by activity and body weight

Observations from the table:

• Jump rope at 11.0 MET burns 4.4× more calories per hour than yoga at 2.5 MET — a substantial difference relevant for people optimising calorie expenditure within limited training time.
• Swimming and weight training have the same MET (6.0) and therefore the same estimated calorie burn at equal duration and body weight. This is a useful reminder that the MET method does not distinguish between activities by type — only by energy demand. A vigorous weight training session can burn as many calories as a moderate swim.
• The difference in calorie burn between a 60 kg and 90 kg person running at the same pace is 294 kcal per hour (588 vs 882) — a 50% difference purely from body mass. This is the dominant individual variable in the MET calculation.
• HIIT at MET 8.0 approaches running-level calorie expenditure in a shorter time, but only if the "high intensity" intervals are genuinely high intensity. A workout marketed as HIIT that is mostly rest periods and low-effort sets will not achieve the assumed MET.

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How Body Weight Changes the Result

Body weight is the most powerful single variable in the MET calorie formula — more influential than activity choice for moderate-duration sessions. This is because the formula is linear in weight: a 20% increase in body weight produces exactly a 20% increase in calories burned for the same activity at the same duration.

Example comparison: Same activity, different weights

The 100 kg person burns 82% more calories in the same 30-minute run than the 55 kg person. This has a counterintuitive implication for weight loss: as a person loses weight, their calorie expenditure per session decreases, requiring either longer sessions or increased intensity to maintain the same energy deficit.

In the heart rate method, weight also appears in the formula but as a smaller coefficient (0.1988 for males, −0.1263 for females) — it adjusts the calorie estimate alongside heart rate, age, and gender rather than dominating it. This means two people of different body weights exercising at the same heart rate will have different Keytel estimates, but the difference will be smaller than the MET method predicts.

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Six Worked Examples

Example 1: 32-Year-Old Female, 30-Minute Yoga Session

Method: MET | Activity: Yoga | MET: 2.5 | Weight: 63 kg | Duration: 30 min

Calories = 2.5 × 63 × 0.5 = 78.75 kcal
Calories per minute = 78.75 / 30 = 2.6 kcal/min

Interpretation: Yoga's calorie burn is low relative to aerobic exercise — less than half a Mars bar per session. Its value is not caloric expenditure but mobility, parasympathetic activation, and injury resilience. A person who does yoga expecting significant caloric contribution to a weight loss programme will need to supplement with higher-MET activities.

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Example 2: 78 kg Male, 45-Minute Cycling Session (MET Method)

Method: MET | Activity: Cycling (moderate) | MET: 6.8 | Weight: 78 kg | Duration: 45 min

Calories = 6.8 × 78 × 0.75 = 397.8 kcal
Calories per minute = 397.8 / 45 = 8.8 kcal/min

Interpretation: A 45-minute moderate cycle burns approximately 400 kcal for a 78 kg person — roughly equivalent to a large bowl of pasta. Three such sessions per week adds ~1,200 kcal of weekly expenditure, the equivalent of a ~0.15 kg fat deficit per week (at 7,700 kcal per kg of body fat) from exercise alone.

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Example 3: 35-Year-Old Male, 45-Minute Run (Heart Rate Method)

Already worked in the formula section: 558.7 kcal, 12.4 kcal/min (82 kg, avg HR 155 bpm, 45 min). See the Heart Rate Method section above for the step-by-step calculation.

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Example 4: 28-Year-Old Female, 20-Minute HIIT Session

Method: MET | Activity: HIIT | MET: 8.0 | Weight: 60 kg | Duration: 20 min

Calories = 8.0 × 60 × 0.333 = 159.8 kcal
Calories per minute = 159.8 / 20 = 8.0 kcal/min

Note on HIIT post-exercise oxygen consumption (EPOC): The MET formula captures only the calories burned during the session itself. HIIT generates a meaningful post-exercise oxygen consumption (EPOC) effect — the body continues burning calories at an elevated rate for 12–24 hours after a high-intensity session as it restores metabolic homeostasis. Studies estimate EPOC from HIIT adds 6–15% on top of the in-session calorie burn, meaning the true total calorie cost of this 20-minute session is closer to 170–185 kcal. The calculator does not model EPOC; bear this in mind when comparing HIIT against steady-state cardio.

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Example 5: 45-Year-Old Male, 60-Minute Rowing Session (Heart Rate Method)

Method: Keytel | Gender: Male | Age: 45 | Weight: 88 kg | Avg HR: 148 bpm | Duration: 60 min

rate = −55.0969 + 0.6309 × 148 + 0.1988 × 88 − 0.2017 × 45
     = −55.0969 + 93.3732 + 17.4944 − 9.0765
     = 46.694 kJ/min

Calories = (46.694 / 4.184) × 60
         = 11.16 × 60
         = 669.8 kcal

Calories per minute: 11.2 kcal/min. MET method comparison (rowing, MET 7.0, 88 kg, 60 min): 7.0 × 88 × 1.0 = 616 kcal. The heart rate method estimates 54 kcal more because 148 bpm at age 45 represents a higher relative effort than the MET 7.0 assumption implies for this individual.

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Example 6: 67-Year-Old Female, 40-Minute Walking Session

Method: MET | Activity: Walking (moderate) | MET: 3.3 | Weight: 68 kg | Duration: 40 min

Calories = 3.3 × 68 × 0.667 = 149.7 kcal
Calories per minute = 149.7 / 40 = 3.7 kcal/min

Interpretation: Walking is often undervalued because the per-minute calorie burn is modest. But 40 minutes of daily walking at this pace produces approximately 1,050 kcal per week — contributing meaningfully to total energy expenditure, improving cardiovascular health markers, and producing joint-friendly mechanical loading. For a 67-year-old, the low injury risk and high adherence rate of walking often outperforms higher-MET activities in practice.

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Why "Calories Burned" Numbers Are Always Estimates

The output of any exercise calorie calculator — including this one — is an estimate, not a measurement. Understanding why this is the case prevents over-reliance on the numbers and helps set realistic expectations for weight management.

MET values are population averages. The Ainsworth Compendium MET values were derived from studies of many people performing standardised activities. Your individual oxygen consumption at "moderate running pace" may be 10–25% higher or lower than the population mean depending on your running economy, body composition, fitness level, and biomechanics. The formula has no way to access this individual variation.

Fitness level inverts the expected relationship. A fitter runner is more metabolically efficient — they consume less oxygen and burn fewer calories per kilometre than a less fit runner at the same pace. This means the MET method slightly overestimates calorie burn for highly trained athletes and slightly underestimates it for sedentary individuals beginning a new activity.

Heart rate is influenced by non-exercise factors. Caffeine, sleep deprivation, heat, dehydration, emotional stress, and illness all elevate resting and exercise heart rate without correspondingly elevating energy expenditure. A runner who ingested two coffees before their session and is running in warm weather will have a higher average heart rate — and therefore a higher Keytel estimate — than on a cool morning without caffeine, even if the physiological calorie burn is identical.

The formula does not include basal metabolic rate (BMR). The calories calculated here represent the additional expenditure from exercise above resting metabolism. They do not include the ~60–70 kcal per hour your body burns at rest simply to maintain organ function. Total daily energy expenditure (TDEE) includes BMR, the thermic effect of food, non-exercise activity thermogenesis (NEAT), and exercise calories combined.

Calorie content of food varies. Even if the exercise estimate were perfect, the calorie content of food has its own measurement error of ±10–20% due to variation in cooking methods, food quality, and database inaccuracy. Weight management calculations that combine food intake and exercise expenditure therefore carry compounding uncertainty — the signal is real but the precision is limited.

Use the output directionally: running for 30 minutes burns meaningfully more calories than walking for 30 minutes; exercising for 60 minutes burns more than 30 minutes at the same intensity. The relative comparisons are reliable even when the absolute numbers carry ±15% error.

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Calorie Burn and Weight Loss: What the Numbers Mean

The relationship between exercise calorie expenditure and body weight change is real but frequently misunderstood. The following framework contextualises the calculator's output for weight management purposes.

The energy balance equation: Body weight change is governed by the difference between total energy intake (calories consumed) and total energy expenditure (BMR + NEAT + exercise + thermic effect of food). A sustained deficit causes fat loss; a sustained surplus causes fat gain.

One kilogram of body fat contains approximately 7,700 kcal. This is the most useful single number for contextualising exercise calorie burns. To lose 0.5 kg per week purely through exercise — without changing diet — requires burning an extra 3,850 kcal per week above baseline, equivalent to approximately 550 kcal per day of additional exercise every single day. For most people, this is 50–70 minutes of running daily on top of normal activity. This is why exercise alone without dietary adjustment is a slow path to weight loss.

The role of exercise is compound: Exercise creates a direct calorie deficit, but it also increases resting metabolic rate through muscle mass gains, improves insulin sensitivity, regulates appetite hormones, and produces structural adaptations (increased mitochondrial density, improved cardiovascular efficiency) that elevate NEAT — the unconscious low-level physical activity that constitutes 20–30% of total daily expenditure. These indirect effects often exceed the direct calorie burn of a single session over a training career.

Practical weight management benchmarks:

The most sustainable and evidence-supported approach combines modest dietary reduction (300–500 kcal/day) with regular exercise — with neither component at an extreme. Exercise provides the metabolic benefits; dietary adjustment provides the majority of the energy deficit.

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Assumptions and Notes

• MET formula source. Calories = MET × weight(kg) × duration(hours). MET values sourced from: Ainsworth BE et al. (2011). 2011 Compendium of Physical Activities: a second update of codes and MET values. Medicine & Science in Sports & Exercise, 43(8), 1575–1581.
• Heart rate formula source. Keytel LR et al. (2005). Prediction of energy expenditure from heart rate monitoring during submaximal exercise. Journal of Sports Sciences, 23(3), 289–297. https://doi.org/10.1080/02640410400022185
• kJ to kcal conversion. 1 kcal = 4.184 kJ (exact thermochemical definition).
• MET values used in this calculator. Walking 3.3 | Running 9.8 | Cycling 6.8 | Swimming 6.0 | Jump Rope 11.0 | Rowing 7.0 | Yoga 2.5 | HIIT 8.0 | Weight Training 6.0. These represent typical moderate effort for each activity category per the 2011 Compendium.
• Accuracy limitations. Both methods produce population-level estimates with individual error of ±10–20%. They are not medical measurements. Persons with cardiovascular conditions, metabolic disorders, or those requiring precise energy tracking for clinical purposes should work with a registered dietitian or exercise physiologist.

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Further Reading

• Running Pace Calculator: Pace, Speed, and Riegel Race Time Predictions
• VO2 Max Calculator: Estimate Aerobic Capacity Across Five Test Methods
• Heart Rate Zone Calculator: Five-Zone Training Framework from Max HR

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        "text": "MET stands for Metabolic Equivalent of a Task. A MET of 1.0 represents the energy expended sitting quietly — approximately 3.5 mL of oxygen per kilogram per minute. All other activities are expressed as multiples of this resting baseline: a MET of 6.0 burns six times the energy of sitting quietly at the same body weight and duration. MET values are standardised in the Ainsworth Compendium of Physical Activities."
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        "text": "For sustained aerobic exercise (running, cycling, swimming, rowing), the heart rate method (Keytel formula) is more accurate because it personalises the estimate to your individual cardiovascular response. For resistance training, yoga, or activities where heart rate does not closely track metabolic demand, the MET method is preferred. For quick estimates without heart rate data, the MET method is entirely adequate."
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        "text": "Nutritional calories (used on food labels) are kilocalories — 1 Calorie (capital C) = 1 kcal = 1,000 small calories. This calculator outputs kcal, which is directly equivalent to the Calories shown on food packaging. The terms are used interchangeably in exercise science."
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      "name": "How many calories does 30 minutes of running burn?",
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        "text": "For a 70 kg person running at a moderate pace (MET 9.8), 30 minutes burns approximately 343 kcal. For a 90 kg person the same run burns 441 kcal; for a 55 kg person, approximately 269 kcal. Running pace matters significantly — slow jogging (MET ~6.0) burns roughly 40% fewer calories per minute than vigorous running (MET ~11.0+)."
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      "name": "Does HIIT burn more calories than steady-state cardio?",
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        "text": "During the session itself, HIIT and steady-state cardio at equivalent average intensity burn similar calories per minute. HIIT's advantage is the post-exercise oxygen consumption (EPOC) effect — the elevated metabolic rate maintained for 12–24 hours after a high-intensity session adds an estimated 6–15% to total calorie expenditure. HIIT also achieves equivalent cardiovascular adaptations in less time."
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        "text": "The negative weight coefficient for women in the Keytel formula reflects differences in body composition. Women, on average, carry a higher proportion of body fat relative to lean mass than men at the same weight. Because fat tissue has lower metabolic activity than muscle, a heavier woman does not burn as many additional calories per kilogram as a heavier man would. The formula encodes this population-level physiological difference."
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        "text": "Yes, using the MET method with a MET value of 6.0 (general) or up to 8.0+ for vigorous sessions. The heart rate method is not recommended for weight training because heart rate during resistance exercise is influenced heavily by breath-holding patterns and rest intervals, which do not correlate cleanly with oxygen consumption the way sustained aerobic exercise does."
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      "name": "How accurate are calorie burn estimates from fitness trackers?",
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        "text": "Consumer fitness tracker calorie estimates typically carry ±20–30% error. This calculator's MET method has similar accuracy (±15–20%); the heart rate method with a quality chest-strap monitor achieves ±10–15%. Wrist-based optical heart rate sensors are less accurate than chest straps, particularly during high-intensity or arm-movement-heavy activities."
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        "text": "EPOC (Excess Post-exercise Oxygen Consumption) is the elevated metabolic rate maintained after exercise as the body restores oxygen stores, clears metabolic byproducts, and repairs tissue. High-intensity and HIIT sessions generate the most EPOC. This calculator estimates only calories burned during the exercise session itself and does not model EPOC. For HIIT, adding approximately 10% to the session estimate accounts for the most likely EPOC contribution."
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        "text": "Total calories burned during exercise includes both the exercise expenditure and the resting metabolic rate you would have burned during that time anyway. Net calories burned subtracts the resting BMR, leaving only the additional expenditure attributable to exercise. This calculator outputs total calories burned, consistent with how calorie burns are reported on most fitness platforms and food labels."
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      "name": "How many calories should I burn per day through exercise?",
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        "text": "Current physical activity guidelines (WHO, CDC, ACSM) recommend at least 150–300 minutes of moderate-intensity aerobic activity per week, equivalent to approximately 1,000–2,000 kcal of weekly exercise expenditure for a 70 kg person — roughly 150–300 kcal per day. This is a health maintenance target. For active weight loss, higher expenditure combined with modest dietary reduction is recommended."
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