14 May 2018

Healthy eating and nutrition in middle age and beyond

From Afternoons with Jesse Mulligan, 2:29 pm on 14 May 2018

Eating ‘real food’ is a good start for a healthy middle age, says nutrition expert David Cameron-Smith.

Stew with lamb, potatoes and other vegetables.

Photo: 123rf

David Cameron-Smith, professor of nutrition at the Liggins Institute, says we reach our physiological peak between the ages of 25 and 30 and then it’s a slow decline.

And along the way we fall into habits that might not serve us well in middle age and beyond.

Cameron-Smith is an expert on ways to stay healthy as we age. He shares some tips and debunks a few food myths.

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Photo: supplied

Studies of populations who live longer than average show they eat “real food” in season rather than processed meals and, most importantly, Cameron-Smith says, they don’t eat too much food.

“Gaining weight, and all the diseases associated with gaining weight, carry a very significant health burden,” Cameron-Smith says. “Heart disease, diabetes, cognitive decline and even some cancers are all related to getting too much food and growing old”.

The best diet is focused on vegetables, fruits, grains, legumes and pulses, says Cameron Smith.


Look for slowly digested carbohydrates, he says, Most processed food has carbohydrates that are a rapid source of energy.


Long-chain polyunsaturated fats essential for health. Plant-based fats (with the exception of tropical oils such as palm oil and coconut oil) and long chain omega-3 fats from seafood are healthy fats.


Weight-bearing exercises are important in stimulating your muscles to repair themselves, adapt and respond.

Using your muscles – anything from gardening to a gym class – is fundamental for middle age.


A Liggins Institute study last year found older men need more protein than recommended in international guidelines to maintain muscle strength. Cameron-Smith recommends eating high protein foods around the time of exercise.

In general, getting high protein foods in all three daily meals is probably beneficial in middle age, he says.


For vegetarians, beans, legumes and foods like tofu are sources of protein.

“Being a vegetarian … certainly involves expanding your range of foods rather than contracting your range of foods.

“But there’s no health deficits in being a vegetarian and the evidence suggests it’s probably beneficial in the longer term for many people in terms of their health.”


Being inactive, gaining weight, and diet contribute to inflammation, which in turn drives conditions such as cognitive decline, Cameron-Smith says.

Eating vegetables, grains and cereals and avoiding rapidly digested carbohydrates, foods that are high in fat and salt, and to a lesser extent alcohol, will manage inflammation.

Fasting and diets

Humans are adapted to and capable of surviving lean periods, Cameron-Smith says.

Fasting, approached with a certain amount of care, won’t do you any harm.

But clinical research studies show it’s no better for weight loss than a prudent diet where you reducing calories.

Ketogenic diets - reducing carbs so the body turns fat into ketones for use as energy - are popular among sports people at the moment, but Cameron-Smith says there’s little evidence it makes you stronger and faster.

Diet obsessions

It’s important not to obsess about our diet – we need to enjoy and savour food, but make it the best food we can get our hands on.

“Middle age is a period where you’re under enormous pressure … you should have a regime that works for you, is enjoyable and it adds to your life.”