Protein supplements, how much protein you need and when to take care

How much protein you need

In the UK, the reference intake for adults aged 19 to 64 is 55.5 g of protein a day for men and 45.0 g for women [1]. Most people reach this from ordinary meals that include fish, meat, eggs, dairy, beans, lentils, tofu or nuts.

Protein needs rise in later life, and the European Society for Clinical Nutrition and Metabolism (ESPEN) advises that older people eat at least 1 g of protein per kg of body weight each day, adjusted for nutritional state, activity, illness and tolerance [2]. For someone who weighs 70 kg, that is at least 70 g a day. An international expert group, PROT-AGE, suggests 1.0 to 1.2 g per kg for people over 65, and 1.2 to 1.5 g per kg for most older people with an acute or long-term illness [3].

Protein, muscle and sarcopenia

Sarcopenia is the loss of muscle strength and mass that becomes more common with age, though it can begin earlier in life. The European consensus places low muscle strength at the centre of the diagnosis, confirmed by measures of muscle quantity and physical performance [4].

Protein works best alongside activity, and PROT-AGE recommends endurance and resistance exercise at a level that is safe for each person, and at least 1.2 g of protein per kg for older people who exercise or are otherwise active [3]. ESPEN notes that weight loss in later life, whether intended or not, speeds the loss of muscle and raises the risk of sarcopenia and frailty, so any weight loss plan should keep protein at 1 g per kg or more [2].

What a supplement adds to strength training

A meta-analysis of 49 trials with 1,863 healthy adults found that protein supplements added to the gains in muscle size and strength from resistance training lasting 6 weeks or more [5]. The benefit was smaller with increasing age, and total protein intakes above about 1.62 g per kg a day brought no further gain in lean mass [5].

The International Society of Sports Nutrition suggests 1.4 to 2.0 g per kg a day for most people who exercise, and says these needs can be met from whole foods, with a supplement as a practical option when food alone is hard to arrange [6].

A protein product sold as a food may carry only the health claims on the authorised register in Great Britain, such as that protein contributes to a growth in muscle mass and to the maintenance of muscle mass and normal bones [7].

Who should check with a doctor first

Kidney disease is the main reason to take care. International kidney guidelines suggest 0.8 g per kg a day for adults with moderate to severe chronic kidney disease, and advise avoiding more than 1.3 g per kg in those at risk of their disease progressing [8]. The same guidelines suggest higher targets for older adults with frailty or sarcopenia, so the right amount is a balance a doctor should strike with you [8].

• You have chronic kidney disease, or a blood test has shown reduced kidney function [8].
• You are older and losing weight without trying, which calls for an assessment of its own [2].
• You plan to lose weight in later life and want to protect your muscle while you do [2].
• You are acutely or chronically unwell, when needs can rise to 1.2 to 1.5 g per kg [3].

Choosing a protein supplement

In the UK, a protein powder or drink sold as a food supplement is regulated as food. It is not a medicine and is not intended to treat or prevent disease [9]. Its label must list the ingredients with allergens emphasised, the recommended daily amount and a statement that a supplement is no substitute for a varied diet [9].

Compare the protein per serving, check for milk, soy or other allergens, and look for a product built on a complete protein, because the essential amino acids are what drive muscle protein building [6]. Start with what you eat, spreading protein across your meals through the day. A supplement works best as a top-up to meals, and it adds energy as well as protein, which matters if you are managing your weight.

How The Wellness can help

A GP appointment lets a doctor look at your weight, strength, diet, medicines and kidney function together, and agree a protein target that suits your age and health. If you would like support with strength or weight, the doctor can plan the next steps with you and explain any blood results in plain words.

Once you know what you need, The Wellness shop stocks protein products you can choose with that advice in hand. Every doctor is GMC registered, our clinics are on Baker Street in Marylebone and Eccleston Street in Belgravia, and a doctor can come to your home or hotel in London.