TempoLife › Features › Calorie needs by life stage › teenager-boys
Teenage boys (14-18): calorie and protein needs
Adolescent energy needs are driven by growth and by an activity level that swings wildly between term-time sport and school holidays. No prediction equation handles that well, and this page is honest about which parts it cannot do.
These are population averages, not a plan for you. Energy and protein needs in teenage boys (14-18) are individualised by a midwife, doctor or registered dietitian who knows your history, your measurements and your blood work. Do not use this page to decide to eat more or less than you have been told to.
GrowthMenReference age 16
The equation used everywhere on this site — Mifflin-St Jeor — was derived and validated in adults. Under 18, the reference bodies do not use it. WHO/FAO and EFSA build adolescent energy requirements from age- and sex-specific equations plus an allowance for the energy deposited in new tissue during growth. The table below still uses Mifflin-St Jeor for consistency, and you should read it as a floor with wide error bars rather than a target.
The reason it is still useful is the shape rather than the value. It shows how much of an adolescent's requirement is driven by body size and how much by activity, and the answer is that activity dominates. A 70 kg sixteen-year-old at PAL 1.4 and the same boy at PAL 2.0 differ by something like a thousand kilocalories a day. That is the whole reason "he eats constantly and never gains" and "he barely eats and gains" are both normal observations about different boys in the same class.
The growth spurt adds a second complication: it is not evenly spread. Energy and protein deposition peaks during the spurt and falls afterwards, so appetite genuinely does swing over months. Treating a teenager's intake as a number to be controlled, in either direction, is the failure mode this page is most worried about. If there is a concern about growth, weight or eating behaviour, that belongs with a doctor or a paediatric dietitian, not a calculator.
The adjustment for this stage
No fixed increment — growth is handled through activity level and the growth spurt, not a flat addition.
PAL 1.75 sits in the moderately-to-vigorously-active band. Adolescents in sport frequently sit above 2.0 on training days and near 1.4 on holidays — the swing is enormous.
Source: Human energy requirements — Joint FAO/WHO/UNU Expert Consultation (physical activity level framework) · checked 2026-09-02
The equation this page uses
BMR (men) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
BMR (women) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Daily target = BMR × 1.75Worked through for the middle row of the table below: a man of 70 kg and 180 cm at age 16 has a Mifflin-St Jeor BMR of about 1 750 kcal. Multiplied by PAL 1.75 that is 3 063 kcal, which is the daily estimate.
Worked example: by height and weight
| Body weight | 165 cm | 172 cm | 180 cm | 188 cm |
|---|---|---|---|---|
| 50 kg | 2 548 | 2 625 | 2 713 | 2 800 |
| 60 kg | 2 723 | 2 800 | 2 888 | 2 975 |
| 70 kg | 2 898 | 2 975 | 3 063 | 3 150 |
| 80 kg | 3 073 | 3 150 | 3 238 | 3 325 |
| 90 kg | 3 248 | 3 325 | 3 413 | 3 500 |
Worked example: how age moves it
| Age | 50 kg | 60 kg | 70 kg | 80 kg | 90 kg |
|---|---|---|---|---|---|
| 14 | 2 730 | 2 905 | 3 080 | 3 255 | 3 430 |
| 15 | 2 721 | 2 896 | 3 071 | 3 246 | 3 421 |
| 16 | 2 713 | 2 888 | 3 063 | 3 238 | 3 413 |
| 17 | 2 704 | 2 879 | 3 054 | 3 229 | 3 404 |
| 18 | 2 695 | 2 870 | 3 045 | 3 220 | 3 395 |
What changes if your activity is different
| Activity level | What it describes | kcal a day |
|---|---|---|
| PAL 1.4 | Sedentary or low activity — desk work, little planned exercise | 2 450 |
| PAL 1.6 | Moderately active — some walking, light training two or three times a week | 2 800 |
| PAL 1.8 | Active — on your feet at work, or training most days | 3 150 |
| PAL 2.0 | Very active — physical job plus training, or high training volume | 3 500 |
Protein for this stage
EFSA's population reference intake for adolescents is around 0.9 g of protein per kg of body weight a day, slightly above the 0.83 g/kg adult value, and sports bodies work at the upper end for those training hard.
| Body weight | Protein, lower g/day | Protein, upper g/day | kcal from the lower figure | Share of the daily estimate |
|---|---|---|---|---|
| 50 kg | 45 | 50 | 180 | 7% |
| 60 kg | 54 | 60 | 216 | 7% |
| 70 kg | 63 | 70 | 252 | 8% |
| 80 kg | 72 | 80 | 288 | 9% |
| 90 kg | 81 | 90 | 324 | 9% |
Source: Human energy requirements — Joint FAO/WHO/UNU Expert Consultation (physical activity level framework) · checked 2026-09-02
Your own numbers
Calculate it for your own body
JavaScript is off, so use the worked-example tables on this page — they are computed on the server from the same equation.
Protein band on this page: EFSA's population reference intake for adolescents is around 0.9 g of protein per kg of body weight a day, slightly above the 0.83 g/kg adult value, and sports bodies work at the upper end for those training hard.
The nutrients that matter most here
- Calcium. Peak bone mass is largely built in adolescence and cannot be built later. This is the single most time-limited nutrient on the page.
- Vitamin D. Works with calcium for the same time-limited reason, and northern winters supply none from skin.
- Iron. Requirements rise during the growth spurt as blood volume and lean mass increase.
- Zinc. Involved in growth and tissue repair; shellfish, meat, seeds and legumes carry the most in the USDA reference data.
- Protein. Not usually a problem in this group, but it becomes one where sport volume is high and eating is chaotic.
Source: EFSA Dietary Reference Values — energy, protein and micronutrients (European Food Safety Authority) · checked 2026-09-02
Nutrient reference values are population figures. This page never tells you to take a supplement or how much of one to take — that is a decision for a clinician who can see your blood work and your medicines.
What to actually do
- Match intake to the training week, not to a flat daily figure — hard days and rest days are genuinely different.
- Keep calcium sources in the day; peak bone mass has a deadline that other nutrients do not.
- Anchor breakfast. Skipped breakfast plus afternoon sport is the most common avoidable gap in this group.
- Treat sudden changes in appetite, weight or attitude to food as a reason to talk to a doctor, not to change a number.
Frequently asked questions
Is Mifflin-St Jeor valid for a 16-year-old?
Not really. It was developed in adults. Reference bodies use age-specific equations plus a growth allowance for under-18s. The table here is shown as a rough floor and labelled as one.
How much protein does a teenage athlete need?
The adolescent population reference intake is around 0.9 g per kg of body weight a day, and sports bodies work at the upper end of the adult athlete range for those training hard. Both are population figures.
Which equation is this based on?
Mifflin-St Jeor for the resting figure, multiplied by a physical activity level of 1.75, with no flat increment for this stage.
Can I use this instead of seeing a professional?
No. These are population reference values. A midwife, doctor or registered dietitian is the only person who can turn them into a plan for you.
Other life stages
Pregnancy, first trimester
about +70 kcal a day on top of the pre-pregnancy requirement
Pregnancy, second trimester
about +260 kcal a day on top of the pre-pregnancy requirement
Pregnancy, third trimester
about +500 kcal a day on top of the pre-pregnancy requirement
Breastfeeding
about +500 kcal a day while breastfeeding exclusively
Teenage girls (14-18)
no fixed increment — growth is handled through activity level and the growth spurt, not a flat addition
Adults over 65
no addition — the requirement falls with lean mass and activity, while the protein target rises
All life stages · TDEE calculator · Macro split · Exercise library · Nutrient toplists
A reference value is a starting point, not an answer
Log two weeks in TempoLife and you have your own figure — what you ate, what you moved, and what your weight actually did.