Blood sugar spikes may be being caused by staple foods we all eat believing them to be healthy. These foods are among the most popular in the human diet: potatoes, bread and rice.

The reason they might be causing our blood sugars to spike is because they all contain starchy carbohydrates. These are carbs that are broken down very easily by the body and quickly turned into sugar, potentially causing blood sugar levels to spike. In the long term, repeated spikes in your blood sugar can cause heart problems, kidney problems, problems with eyesight and nerve issues like neuropathy, where you lose feeling in fingers and toes.

This is not to say that these foods are outright unhealthy but it is a good idea to try and combine them with other foods, particularly ones high in fibre and healthy fats, which slow down the conversion into sugar and the rate at which it is absorbed into your blood stream, making blood sugar spikes less pronounced. The effect on blood sugar also depends on an individual’s blood sugar control, which may be good or bad and is largely genetic.

The surprising situation was explained by Professor Tim Spector on the Zoe podcast. He said that although starchy carbs included a lot of the mass-produced snacks we eat, including the likes of Pringles and Doritos, they also included staples like potatoes, rice, bread and pasta.

Professor Spector said: “Most people are eating potatoes, rice, bread evey single day and you only have to ask a family doctor, when they have a patient with diabetes or pre-diabetes and you ask about their diet, it’s nearly all potatoes, rice and toast, which they’ve been told was good because it’s low fat.”

He said it was key to understand how quickly particular carbohydrates were dissolved in your body: “If you’re having some white rice or you’re having a pasta or you’re having a potato, they’re all starchy carbs which are transformed fairly rapidly into sugars.

“The idea that potatoes are a healthy food, for most people that’s not true. I mean, they’re a very good source of nutrition but in the modern world I think we’re probably eating too much of them. We’re too reliant on bread, potatoes and white rice and, to some extent, pasta — although pasta has some other advantages. It’s got more fibre in it, it’s got more protein etc.”

Prof Spector said that we should consider these foods more of a treat than an everyday staple: “I’m not saying you should never have these foods. I’m just saying that if you’re having them on a regular basis and you’re susceptible, because not everyone is as susceptible, then it’s a problem.

“If you’re having some white rice, you’re having pasta, they’re all starchy carbs which convert very quickly into sugar, gives you a sugar spike in your blood, and people who have these big spikes, they’re consistently hungrier than people that don’t.”

Asked what carbohydrates he ate, Prof Spector said: “Those that contain fibres, that [are] slightly harder to digest. If you have 5g of extra fibre every day that will reduce your risk of heart disease and early death by 14%.”

Which carbohydrates contain fibre?

Carbohydrates that contain fibre include:

• oatmeal
• wholegrain cereal
• bulgur
• figs
• beans
• berries
• sweet potatoes.

Fibre helps your gut microbiome, and “can help keep your bowels healthy and can help you feel full, which means you’re less likely to eat too much”, says the NHS. This means it’s a helpful nutrient for losing weight. You may also be able to lower your blood sugar levels with a shot of one drink every day, according to research.