Blood Sugar: A Guide for the 6 Million UK Adults at Risk

In February 2025, Diabetes UK released figures that stopped people in their tracks. One in five UK adults now lives with either diabetes or prediabetes. That is 12.1 million people. Of those, 4.6 million have a diabetes diagnosis. A further 1.3 million have Type 2 diabetes but do not know it yet. And 6.3 million have prediabetes, a state where blood sugar levels are elevated but not yet high enough for a diabetes diagnosis.

Prediabetes is not a harmless waiting room. Without intervention, roughly 5-10% of people with prediabetes progress to Type 2 diabetes each year. But here is the number that matters: research has consistently shown that combined lifestyle interventions, including diet, physical activity, and sustained weight loss, can reduce the risk of developing Type 2 diabetes by approximately 50%.

Half. That is not a marginal improvement. That is flipping a coin from landing on diabetes to landing on not-diabetes. And the dietary changes required are not dramatic. They are specific, achievable, and grounded in decades of clinical evidence.

What blood sugar actually is

Your body converts carbohydrates from food into glucose, which enters your bloodstream and is transported to cells for energy. Insulin, produced by your pancreas, is the hormone that allows glucose to enter cells. When this system works properly, blood sugar rises modestly after eating and returns to baseline within a couple of hours.

In prediabetes and Type 2 diabetes, this system starts to malfunction. Your cells become resistant to insulin (insulin resistance), meaning your pancreas has to produce more and more insulin to achieve the same effect. Eventually, the pancreas cannot keep up, blood sugar stays elevated for longer, and damage begins to accumulate: in your blood vessels, your nerves, your kidneys, your eyes, and your heart.

The key insight is that insulin resistance does not appear overnight. It develops gradually over years, driven by excess visceral fat (fat around the organs, not just subcutaneous fat you can see), physical inactivity, poor diet quality, and genetic predisposition. By the time blood sugar is high enough for a diabetes diagnosis, insulin resistance has been present for years.

This means there is a long window of opportunity to intervene. Prediabetes is that window.

The dietary changes that actually matter

1. Reduce refined carbohydrates and added sugars

This is the highest-impact single change for blood sugar management. Refined carbohydrates (white bread, white rice, white pasta, pastries, cakes, biscuits) and added sugars (in fizzy drinks, fruit juice, confectionery, sweetened cereals, sauces) cause rapid blood sugar spikes because the fibre and food matrix that would normally slow absorption have been removed through processing.

Swapping refined for whole is the practical intervention. Wholemeal bread instead of white. Brown rice instead of white. Oats instead of sugary cereal. Whole fruit instead of fruit juice. You do not need to eliminate carbohydrates. You need to change their form.

The sugar-sweetened drink category deserves specific mention. A single 330ml can of regular cola contains roughly 35g of sugar, equivalent to nearly nine teaspoons. Consumed as a liquid, this sugar enters the bloodstream extremely rapidly because there is no fibre, fat, or protein to slow absorption. Switching from regular soft drinks to water, sparkling water, or sugar-free alternatives is one of the simplest and most effective blood sugar interventions available.

2. Include protein with every meal

Protein slows the absorption of carbohydrates from the same meal, reducing the post-meal blood sugar spike. It also promotes satiety, helping with the weight management that is central to prediabetes reversal.

A meal of plain pasta with tomato sauce will produce a much larger blood sugar spike than the same pasta served with chicken, fish, or lentils. Adding protein does not reduce the total carbohydrate content. It changes the speed at which the carbohydrate reaches your bloodstream.

Practical UK examples: eggs with toast instead of toast alone. Chicken or tuna in a sandwich rather than just bread and salad. Greek yoghurt with fruit instead of fruit alone. Beans or lentils added to rice dishes.

3. Prioritise fibre

Soluble fibre (found in oats, barley, beans, lentils, apples, and citrus fruits) forms a gel in the gut that physically slows carbohydrate absorption. The evidence for fibre in blood sugar management is strong and consistent. The UK recommendation is 30g per day. Most adults achieve about 18g.

One study found that for every 10g increase in daily fibre intake, the risk of developing Type 2 diabetes decreased by 25%. That is a substantial effect from a single dietary variable.

The easiest ways to increase fibre: start the day with porridge (beta-glucan in oats is particularly effective for blood sugar control), eat vegetables with every meal, choose wholegrain versions of bread, rice, and pasta, include legumes (lentils, chickpeas, beans) several times a week, and snack on fruit with skin rather than fruit juice.

4. Manage portions, especially of carbohydrate-dense foods

You do not need to count calories or weigh food. But being aware of carbohydrate portions at each meal helps avoid the blood sugar spikes that come from large carbohydrate loads.

A practical heuristic: carbohydrate foods (rice, pasta, bread, potatoes) should occupy roughly a quarter of your plate. Vegetables should fill half. Protein should fill the remaining quarter. This is essentially the NHS Eatwell Guide proportions, and it works well for blood sugar management without requiring any calculation.

5. Consider meal timing

Eating regular meals, roughly spaced every 3-5 hours, helps maintain stable blood sugar levels. Skipping meals and then overeating produces large glucose spikes. Late-night eating, particularly of carbohydrate-heavy foods, can disrupt overnight blood sugar regulation.

Some evidence supports eating your largest meal earlier in the day rather than later, when insulin sensitivity tends to be higher. A substantial breakfast and moderate dinner, rather than skipping breakfast and eating heavily in the evening, aligns better with your body's circadian glucose metabolism.

The foods that help most

Oats. The beta-glucan in oats is one of the most evidence-based food components for blood sugar management. A daily bowl of porridge is a genuinely therapeutic food for prediabetes.

Legumes. Lentils, chickpeas, kidney beans, black beans. High in fibre, high in protein, low glycaemic index. A tin of lentils added to a curry or soup is one of the cheapest and most effective blood sugar interventions in the supermarket.

Non-starchy vegetables. Broccoli, spinach, peppers, courgettes, green beans, cauliflower, tomatoes, leafy greens. These provide fibre, micronutrients, and volume with minimal impact on blood sugar.

Nuts. A small handful (30g) of almonds, walnuts, or mixed unsalted nuts. Healthy fats and protein with minimal carbohydrate. Several studies have linked regular nut consumption with reduced diabetes risk.

Oily fish. Salmon, sardines, mackerel. The omega-3 fatty acids may improve insulin sensitivity, and the protein content helps balance meals.

Vinegar. There is modest but consistent evidence that 1-2 tablespoons of apple cider vinegar before a carbohydrate-rich meal can reduce the post-meal blood sugar spike by 20-30%. The mechanism appears to involve slowing gastric emptying and improving insulin sensitivity. It is not a cure, but it is a simple addition with minimal downside.

How MyFoodFit scores for blood sugar management

The blood sugar profile applies modifications that directly target the glycaemic impact of foods.

Sugar penalties are steeper than the general health profile. Products where sugar is the dominant calorie source receive the sugar_dominant derived signal, which applies a -15 penalty. This catches the category of products (many breakfast cereals, cereal bars, flavoured yoghurts, sauces) that appear healthy but are sugar-delivery vehicles.

Fibre receives a stronger positive modifier, reflecting the direct evidence for fibre in blood sugar management.

Protein receives a positive modifier, reflecting its role in slowing carbohydrate absorption.

The scoring does not distinguish between "natural" and "added" sugars in isolation. A fruit smoothie with 30g of sugar per serving receives a lower score than a whole apple with 10g of sugar, even though both sugars are "natural." This is because the smoothie delivers a much larger glucose load with less fibre to moderate absorption. The form of the food matters as much as the source of the sugar.

The NHS Diabetes Prevention Programme

If your GP identifies you as having prediabetes (typically through an HbA1c test showing levels between 42 and 47 mmol/mol), you may be referred to the NHS Diabetes Prevention Programme (NDPP). This is a free, evidence-based programme offering dietary advice, physical activity support, and weight management coaching over approximately nine months.

Take the referral if offered. The programme is based on the same evidence that shows 50% risk reduction through lifestyle change. It provides structured support that is difficult to replicate alone.

If you have not had a recent blood sugar check and you are over 40, overweight, or have a family history of diabetes, ask your GP for an HbA1c test. Diabetes UK's free online Know Your Risk tool takes two minutes and can indicate whether you should be tested.

Prediabetes is reversible. Type 2 diabetes is manageable. But in both cases, earlier intervention produces better outcomes. The dietary changes are not complicated. They just need to start.

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This content is for information only and does not replace medical advice. If you have been diagnosed with prediabetes or diabetes, work with your GP and diabetes team on your dietary management plan.