The benefits of a low-sugar diet, and the foods to eat and avoid

We are constantly told not to consume too much sugar. But not all sugar is bad. Naturally occurring sugars provide fuel for the body in the form of carbohydrates. Locked inside cells, they are found in fruit, vegetables and milk and come with extra nutrients, such as fibre.

The dietary bogeyman is a class of sugars known as “free sugars”. These are the processed and refined sugars added to food and drink, and also the type of sugar found in honey, syrup and fruit juice. They are described as free because they’re not found inside the cells of the food we eat. These are easier to consume without realising and linked to poor diet and elevated blood glucose. Health experts recommend that we limit free sugars in our diet.

The government recommends that sugar should make up no more than 5 per cent of our daily calorie intake, but according to the British Nutrition Foundation, on average in the UK we are consuming between 9 per cent and 12.5 per cent of our calories from free sugars, depending on age group.

What is a low-sugar diet?

Government guidelines recommend that adults should have no more than 30g of sugar a day, which is the equivalent of seven sugar cubes (a can of fizzy drink can contain around nine teaspoons of free sugars). A low-sugar diet should be below the 30g limit. The primary goal of a low-sugar diet is to maintain a healthy level of glucose in the body.

Aisling Pigott is a registered dietitian and spokesperson for the British Dietetic Society. She explains: “From a health perspective, we would consider anything less than 30g of free sugar per day as meeting public health guidance around sugar.”

Lucy Diamond, a registered dietitian and clinical director for Innovation at NHS weight management provider, Oviva, adds: “The goal is to manage and stabilise blood sugar levels, promote overall health, and prevent various health issues associated with high sugar consumption, such as Type 2 diabetes, cardiovascular conditions and obesity.”

What are the benefits of a low-sugar diet?

• Low-sugar diets help with weight loss as excess sugar in the body can turn into fat.
• Consumption of added sugar is associated with a range of life-limiting conditions including fatty liver disease, insulin resistance, Type 2 diabetes, and heart disease.
• In 2010, a World Health Organisation (WHO) literature review found that rates of tooth decay are lower in people whose free sugars intake is less than 10 per cent of total energy intake.
• Studies show that reducing sugar intake can protect the body against inflammation.
• Reducing sugar intake can help improve mood and guard against depression, according to studies.Tips to cut back on sugar.

Tips to cut back on sugar

• Swap sugary drinks for sugar-free versions or water.
• Swap sweet snacks for fresh fruit or something savoury.
• Reduce portion sizes of sugar-laden treats.
• Check labels for foods with high sugar content.
• Keep fruit juices or smoothies to one small glass (150ml) per day.

Foods to include and foods to avoid

The main sources of free sugars in the UK, ie foods to avoid, are:

• Frosted or refined breakfast cereals such as cornflakes and Sugar Puffs
• Sugary drinks
• Fruit juice
• Cakes
• Biscuits
• Desserts
• Sweet spreads such as jam and Nutella
• Sweets and confectionary

Low-sugar foods are:

• Porridge
• Water, tea, coffee
• Beans and legumes
• Non-starchy vegetables such as asparagus, avocado, onions, spinach
• Eggs
• Cheese
• Fish, meat
• Tofu

Eating out on a low-sugar diet 

Rob Hobson, registered nutritionist, advises: “Look out for sauces and marinades as these are probably going to be the greatest source of added sugar. A lot of Asian-style food contains sugar to give it the sweet and savoury flavour. Condiments may also contain sugar to balance the flavours in the recipe. Puddings are also going to be tricky. Fresh fruit is an obvious choice.”

Also avoid sweet chilli dishes, dressings such as honey and mustard and dishes described as “glazed”, “caramelised”, “balsamic” or indeed “sweet”.

Good low-sugar drink choices are red wines, dry white wines and spirits with soda water and lime as a mixer. Stay away from dessert wines, ciders, liqueurs and cocktails.

Tips to overcome sugar cravings

Hobson recommends:

• Include a source of protein, healthy fats and fibre with every meal to prevent blood sugar imbalances that can leave you craving a quick fix between meals.
• Try using spices such as cinnamon and nutmeg in place of sugar as they have a sweet taste and work well sprinkled on yoghurt or added to smoothies or coffee.
• Sniff the scent of vanilla. Some people find this helpful to alleviate sugar cravings.
• Try low-calorie hot chocolate drinks. These use sweeteners that can help to give you the hit you desire without the added sugar.
• Get busy. The evening is one of the times most people crave sweet treats. Try going out for a walk, do something around the house or have a bath with a good book rather than flopping in front of the TV with a packet of Haribo.
• Try drinking a large glass of water when you get a craving. Are you really peckish? Dehydration can be confused with hunger.
• Don’t skip meals. When you get hungry your blood sugar drops and you’re more likely to crave something sweet.

Pigott adds: “If you’re using sugar to sweeten meals, think about adding fruit or sweet vegetables like carrot or butternut squash, which can be effective ways of adding some sweetness without adding free sugar. Also make sure that you are appreciating and enjoying your food. Mindless eating can lead to sugar cravings, where we’re eating on the go a lot, and we’re not necessarily allowing our body to appreciate and enjoy food.”

She also recommends eating nuts with chocolate.

“If you’re having a bar of chocolate, have a handful of nuts with it to help with satiety and allow a slower release of sugar into the bloodstream, rather than mindlessly eating chocolate as you go throughout your day,” she says.

Hidden ingredients to look out for

Hobson says: “Read the label and look out for phrases such as ‘added sugar’ and ingredients such as sucrose, glucose, fructose or anything that ends in –ose, as well as healthier sounding alternatives, such as raw sugar, barley malt, maple syrup, coconut nectar, palm sugar, agave nectar, date sugar and brown rice syrup, which are among sugar’s many guises.”

What the experts think about the low-sugar diet

According to the NHS, sugar found naturally in milk, fruit and vegetables does not count as free sugars and we do not need to cut down on these, although they are included in the “total sugar” figure found on food labels.

Pigott says: “If there isn’t an addition of glucose or a glucose derivative, then it’s likely that sugar is naturally occurring, which is much less detrimental to health and is often absolutely fine to have.”

“A low-sugar diet is a sustainable approach to healthier eating that can lead to significant long-term health benefits. By making informed choices and prioritising whole foods, you can reduce your sugar intake while still enjoying a varied and nutritious diet,” says Diamond.

Risks of a low-sugar diet

Sugars are the body’s main source of energy and while the experts agree that reducing free sugars is a healthy goal, reducing sugar in your diet overall can have adverse effects.

Diamond explains: “While there are many benefits, it’s important to approach a low-sugar diet carefully. The main risk is not getting enough carbohydrates, and therefore not consuming a balanced diet if sugars are cut indiscriminately without incorporating wholegrain carbs. In fact, we should include whole grain carbohydrates as part of a healthy diet, such as brown rice, corn, wholegrain bread and quinoa.

“The important thing is to maintain your blood sugar levels so you don’t become sluggish. For adequate energy levels, dietary plans often call for eating every three to four hours. Several small meals throughout the day is an ideal schedule, and eating more protein and fibre can keep you fuller for longer periods.”

A significant reduction in carbohydrates can lead to energy deficits and nutrient imbalances, so it is recommended to replace high-sugar foods with nutrient-dense alternatives such as fresh fruit and vegetables.

Additionally, if you substitute products containing high levels of free sugars with low-sugar products these are likely to contain artificial sweeteners, which should be consumed in moderation as they are often processed and can be unhealthy. For example, some sweeteners known as polyols, such as sorbitol, xylitol and erythritol, can have a laxative effect if consumed in large amounts.

There is some evidence to suggest that artificial sweeteners can lead to weight gain. One 2005 study by the University of Texas Health Science Center at San Antonio showed that, rather than promoting weight loss, the use of diet drinks was a marker for increasing weight gain and obesity. Those who consumed diet soda were more likely to gain weight than those who consumed naturally sweetened soda.

Consulting with a healthcare professional or dietitian is advisable to ensure you have a balanced and healthy approach to reducing sugar intake.