Plant-based nutrition for older people: how do you find the right balance?

In the future, we will obtain more and more of our proteins from plant sources instead of animal sources. What does this protein transition mean in terms of dietary needs among older people? As we grow older, the way our body processes protein changes. In a webinar by Cosun Nutrition Centre held on 14 December, Dr. Jorn Trommelen and Dr. Ir. Pol Grootswager explained how older people can find a healthy protein balance within a plant-based diet.
23 January 2023

How does muscle building work?

“Building muscle is like building a wall,” says Jorn Trommelen, Assistant Professor of Human Biology at Maastricht University. “Muscle protein synthesis means building blocks from your diet are constantly added to the muscle. At the same time, muscle protein breakdown takes place: exercising causes ‘damage to the wall’. You have to repair this first before you can continue to build”. According to Trommelen, these two processes are in harmony. “After meals you have a positive protein balance, meaning you will be building muscle. In-between meals, the balance is negative. This is usually a stable process measured throughout the day.”

However, there is a big difference in this process between young adults and older people. “Older people respond less strongly to the stimulus of protein. This is called anabolic resistance: when taking in food, muscle protein synthesis increases less rapidly, and decreases less rapidly between meals. The muscles have become less sensitive to food that normally maintains muscle mass”. Trommelen argues that older people must do more to activate that stimulus, especially if they eat more plant-based foods. “Plant-based products contain slightly less of the essential amino acids per gramme of protein than animal proteins. In addition, plant-based products more often have an incomplete amino acid profile and the digestibility of these proteins is also less favourable.  Together this can lead to a deficiency of one or more essential amino acids. If you do not have enough of one of the amino acids, the other amino acids will not be used for muscle building either. You can compare it to building a house. Even if you have all the bricks in the world, if you are short of windows or doors, you will never be able to build a functional house.

Amino acids and exercising

It is possible for older people to get enough protein from a plant-based diet, but according to Trommelen you have to pay attention to a number of things: some products are very high in specific amino acids, but low in others. By mixing the right products you will achieve a healthy amino acid balance. The timing of protein intake is also important. Most people take in their proteins twice during the day, while it is better to divide this over three times. We sometimes solve this with a protein supplement before going to sleep. “Physical effort is indispensable for muscle building. If you don’t, the proteins you take in will not be used for muscle building. Any kind of activity is good. This can be achieved through strength training, or simply by walking; every 1,000 extra steps you take per day already have a positive effect on your protein efficiency. We often see a vicious circle in older people; because they are less mobile, they avoid movement. Whereas they would have to challenge their bodies.”

Risk of malnutrition

“We can see increasing popularity in the Netherlands for plant-based and sustainable foods. This is also the case in hospitals and care institutions, which accommodate lots of older people,” says Pol Grootswagers, Ageing and Nutrition researcher at Wageningen University & Research. “A more plant-based diet does entail a greater risk of protein deficiency. On the one hand because plant-based food is lower in protein and saturates faster and, on the other, because older people have a higher protein requirement. The combination of this increases the risk of malnutrition. A shortage of important micro-nutrients is also lurking. For example, B12 does not occur naturally in plant-based foods, while 25% of older people have a B12 deficiency. You need B12 to carry oxygen in your blood and produce energy. This makes this vitamin very important for mobility, especially among older people.”

Benefits of plant-based diet

Grootswagers states that the protein transition also has a number of important benefits for older people. “For example, a plant-based diet means lower risk of diabetes and it is also related to a lower risk of heart disease. You also increase your fibre in-take and eat less fat. I believe our understanding of finding a healthy balance in a plant-based diet is growing.”


Within Cosun, there’s a strong focus on making plant-based foods healthier and tastier. In the Fascinating program for example, plant-based food ingredients are being developed based on human needs, and crops are selected that suit a sustainable and balanced diet. Also, Cosun Beet Company developed Fidesse®: a high-fibre ingredient that gives plant-based products a pleasant texture and more juiciness.

Jorn Trommelen
You need all essential amino acids in a certain proportion. You can’t build a house with bricks alone, you also need windows and doors.”
Jorn Trommelen
Assistant Professor of Human Biology, Maastricht University