A low-protein, high-carbohydrate diet could be as good for you as drastically reducing calories, new research shows.

The Australian study, published in Cell Reports, shows that a diet high in healthy carbohydrates such as fresh fruit and vegetables and whole grains delivered similar benefits for insulin, blood sugar and cholesterol levels as a 40 per cent cut in calories.

There is already considerable evidence that adopting a calorie-restricted diet boosts metabolic health, helping to protect people against diabetes and cardiovascular disease as they age.

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For most of us, however, such a regime is too punishing to keep up over several years.

“Except for the fanatical few, no one can maintain a 40 per cent caloric reduction in the long term, and doing so can risk loss of bone mass, libido, and fertility,” said the study’s lead author Professor Stephen Simpson of the University of Sydney.

The study compared the effect of different diets on middle-aged mice.

One group of mice was fed a diet with 40 per cent fewer calories than their normal intake. The other group of mice was allowed to eat as much as they wanted – a so-called ad libitum diet.

It is the first time an ad libitum diet low in protein and high in carbohydrates has been shown to have the same benefits as a calorie-restricted one.

“If the study’s results apply to humans, adjusting protein and carbohydrate intake could lead to healthier ageing in a more realistic manner than drastically cutting calories,” Prof Simpson said.

“It still holds true that reducing food intake and body weight improves metabolic health and reduces the risk of diseases like type 2 diabetes, obesity, and fatty liver disease.

“However, according to these mouse data and emerging human research, it appears that including modest intakes of high-quality protein and plenty of healthy carbohydrates in the diet will be beneficial for health as we age.”

Eat more …

• Whole wheat bread
• Oats
• Barley
• Quinoa
• Brown rice

Eat less …

• French fries
• White bread
• Cakes
• Biscuits
• Pastries

Whole grain breads are the way to go, say experts. Photo: Shutterstock

Top tips for adding more healthy carbs to your diet

Start the day right

Options include:

• Porridge made of old-fashioned or steel cut oats (not instant varieties)

• Cold cereals that list a whole grain as the first ingredient. Experts recommend cereals that have at least four grams of fibre and less than eight grams of sugar per serve.

Choose whole grain bread

• The best option is whole grain loaves such as 100 per cent whole wheat bread.

• The next best alternative are loaves that list whole grains such as whole wheat, whole rye or whole grains as the first ingredient.

Lunch on whole grain salads

• Dishes incorporating brown rice or quinoa form a healthy midday meal.

Snack on fruit

• Whole fruit is much better for you than juice. For example, an orange has twice as much fibre and half as much sugar as a 350ml glass of orange juice.

Ramp up your bean intake

• Beans are just as filling as potatoes, but not as fattening. Legumes such as lentils, black beans and chickpeas are a great source of protein and endlessly versatile.

Sources: The Harvard T.H. Chan School of Public Health, Heart Foundation