Protein is everywhere right now. But before you start counting grams or buying protein powder, it helps to know how much you actually need. And that depends on more than your age.

There was a time when protein was mostly associated with bodybuilders and gym regulars. Now, it is difficult to open social media without seeing someone talking about it. Protein bars. Protein shakes. High-protein yoghurt. Protein cereal. Then there is the question of how much protein you are supposed to be eating.

The honest answer is that there is no magic number. For a healthy adult who is not very active, the recommended amount is about 0.8g of protein for every kilogram of body weight each day. If you weigh 60kg, that is about 48g. At 80kg, it is about 64g. The Guardian has previously explored the role of protein in a balanced diet and highlighted common sources such as beans, eggs, fish, meat, milk and yoghurt.

But those numbers are a starting point. Someone who exercises regularly may need more. So might an older person, particularly if they are trying to maintain muscle. And that is where age starts to matter.

Children and teenagers
Children need protein because they are growing. The American Academy of Paediatrics puts the daily requirement at about 13g for children aged one to three, 19g for ages four to eight and 34g for ages nine to 13.

Teenagers need more. Girls aged 14 to 18 need around 46g a day, while boys need about 52g. But this does not mean your child needs a protein shake after school.

A plate of beans, an egg, some fish, chicken, milk or yoghurt can all contribute. For children, it is more important to look at the whole diet than to become fixated on one nutrient. Foods such as eggs and fish are also commonly recommended as part of a nutritious diet for growing children.

20s and 30s
You do not suddenly need a huge amount of protein because you have turned 25 or 30. For most people, 0.8g/kg a day is the basic recommendation.

But exercise changes things. If you run, play sports, lift weights, or are working on building muscle, you may need somewhere around 1.1–1.5g/kg a day, according to guidance from Mayo Clinic.

For a 60kg person, that is roughly 66–90g. You can get there without turning your kitchen into a supplement store. Two eggs at breakfast. Beans and rice at lunch. Fish with plantain at dinner. Milk or yoghurt somewhere in between.

40s and 50s
We start losing muscle as we get older, although the rate is different for everyone. Staying active, particularly with some form of resistance exercise, can help.

Mayo Clinic notes that muscle loss can start in the 40s and 50s. For many people in this age group, 1.0–1.2g/kg a day is a reasonable amount to aim for, particularly if they are active. For someone weighing 60kg, that is 60–72g a day.

One thing worth changing is how you spread it out. If breakfast is tea and bread, lunch is mostly rice and stew, and dinner is when you finally eat a large piece of chicken or fish, you may be making things harder than they need to be. Try to get some protein into each meal instead.

After 65
The European Society for Clinical Nutrition and Metabolism recommends around 1.0–1.2g/kg a day for healthy older adults. People who are unwell, undernourished or recovering from an injury may need more. So, if you weigh 60kg, that is around 60–72g a day.

Professor Stuart Phillips, a researcher at McMaster University who studies muscle and protein, has also looked at how protein is used by older adults. One of the practical takeaways is that it makes sense to spread protein across your meals rather than eating almost all of it at dinner.

That could mean eggs or yoghurt in the morning, beans or fish at lunch, and chicken, meat, or another protein source at dinner. For more ideas on getting protein from everyday Nigerian meals, high-protein lunch ideas include moi moi with boiled eggs, ewa agoyin with eggs and chicken with yam.

No need for protein powder
Protein powder is convenient, but it is not compulsory. There is protein in foods you are probably already eating: beans, eggs, fish, chicken, meat, milk, yoghurt, soy, groundnuts, moi moi, and akara.

The Guardian has previously looked at great sources of protein, including chicken, fish, eggs, oats, soya, Greek yoghurt and protein powder.

Eggs are particularly accessible. One large egg contains about six grams of protein, alongside other nutrients. Eggs are a great source of protein

Dr Walter Willett, professor of epidemiology and nutrition at Harvard, has also highlighted foods such as beans, soy, nuts and whole grains as useful sources of protein alongside other nutrients.

How to count
1–3 years: 13g a day
4–8 years: 19g
9–13 years: 34g
Teen girls, 14–18: 46g
Teen boys, 14–18: 52g
Healthy adults: about 0.8g/kg
Active adults: around 1.1–1.5g/kg
Adults 65+: around 1.0–1.2g/kg

Remember that these figures are guides; pregnancy, breastfeeding, intense exercise, illness and recovery from surgery can change what someone needs. People with kidney disease should also speak with their doctor before increasing their protein intake.

It is also possible to overdo protein. And there are signs you may be taking too much protein, including some of the problems that can arise when protein intake becomes excessive.

A healthy diet still needs carbohydrates, fats, fibre, fruit and vegetables. Your body needs more than one nutrient.