In a study of over 25,000 adults with detailed information about their eating habits, people with a greater diversity of foods in their diet showed a 30 per cent lower risk of developing type 2 diabetes over a ten-year period. 

Unfortunately, the diets with more variety were 18 per cent more expensive than the less-varied ones.

A healthy diet is critical for preventing and managing type 2 diabetes. 

A diet containing all five food groups cuts your diabetes risk by 30 per cent – but can you afford to do it?

Type 2 diabetes affects around 415m adults globally; a figure that is expected to rise to 643m by 2040, mostly in low- and middle-income countries. So governments should support their citizens’ ability to eat well.

For several decades now, governments have recommended that people eat a varied diet. 

Global five-a-day campaigns stress the consumption of a variety of fruits and vegetables. 

The theory goes that consuming a variety of foods ensures that a person receives all the necessary vitamins, minerals and phytochemicals that are needed for the body to function and stay healthy. 

But, what do we really mean by a varied diet and what is its relationship with diabetes?

A varied diet is a healthier diet 

Although dietary guidelines have for a long time recommended eating a variety of foods, scientists are not sure exactly what it is about eating a varied diet that might promote health. 

There has been research on how the variety of foods relate to the nutritional quality of a person’s diet, but little is known about whether the diversity of the diet is related to risk of chronic diseases such as type 2 diabetes.

For example, there are no studies on whether a diet containing foods from all five food groups reduces a person’s risk of type 2 diabetes. 

The gap in price of more and less healthy food is widening, preventing those on lower incomes from eating well

We also don’t know whether the variety of foods within each of the five food groups is important for health.

People’s diets vary in terms of the different food groups. 

For example, one person’s diet might consist mainly of meat and grains while another person’s might contain dairy, vegetables and fruit. 

Diets also vary in the variety of foods within each food group. 


A brisk walk is better than vigorous jogging for keeping diabetes at bay, according to new research.

Doctors advise regular exercise and low-fat diets to improve glucose control in people with pre-diabetes.

But for those who dread the gym, rejoice: a new study by Duke Health has found walking briskly on a regular basis may be more effective than intense exercise. 

The findings are the result of a randomized, six-month study of 150 participants, each of whom was designated as having pre-diabetes based on elevated fasting glucose levels.

Study participants were randomized into four groups. 

The first adopted diet changes, and performed moderate-intensity exercise equivalent to 7.5 miles of brisk walking in a week.

Other study participants were randomly assigned to receive exercise only, using different amounts and intensities. 

On average, participants in the first group had the greatest benefit, with a nine per cent improvement in oral glucose tolerance – a key measure of how readily the body processes sugar and an indicator used to predict progression to diabetes. 

We were interested in analyzing whether the recommendation to consume a wide range of different foods within each food group would have an impact on the risk of developing diabetes.

To do this, we used data collected from middle and older-aged British adults who reported their lifestyles, including their eating habits, when they entered the study and were followed for about ten years. 

We found that people who routinely ate from all five food groups had a 30 per cent lower risk of type 2 diabetes than people who only ate three food groups or fewer. 

Also, people eating the widest variety of fruits and vegetables and dairy products also greatly reduced their risk of diabetes compared with people who had a less varied diet. 

These results could not be explained by other potential risk factors, such as body weight, occupation, income and education, as we took these factors into account in our analysis.

The bill, please 

Research shows that healthy eating is expensive. 

The price gap between more and less healthy foods is growing in the UK and the US and higher food costs may prevent people from eating a healthier diet, particularly those on low incomes. But what about a more varied diet? Is that more expensive, too?

Most epidemiological studies don’t have information about consumer food costs, but our study did because we linked the dietary data to retail food prices. 

We found that diets containing all five food groups were on average 18 per cent more costly than diets containing three food groups or fewer. 

And diets with more variety within each of the five food groups were more costly than diets that contained less variety within each food group.

So, while diverse diets may help prevent chronic diseases, health policymakers will need to acknowledge that the adoption of more varied diets, particularly those containing the most variety of vegetables and fruits, may be substantially more costly and may worsen existing socioeconomic inequalities in diet.

What government can do 

According to the researchers, the government, the private sector and civil society need to bring policy coherence across the food system, including agriculture, business and health in order to tackle the issue

Financial incentives can improve food choices and some local authorities are experimenting with taxes on unhealthy foods, including on sugar-sweetened beverages. 

These are a good start, but financial approaches are no silver bullet.

Tweaking food prices may just be fiddling around the edges if governments don’t also deal with systemic issues such as agricultural policies that are out-of-sync with the dietary priorities most governments advocate. 

And our neighborhood environments, supermarket shelves and portion sizes may be promoting overconsumption of primarily processed, energy-dense foods.

The government, the private sector and civil society need to bring policy coherence across the food system, including agriculture, business and health. 

Easy, affordable access to a varied diet will benefit everyone’s health now and in the future.