What did you eat yesterday? Chances are – even if you’re a healthy eater – there was a bit of a crisp, a biscuit or sneaky stash of chocolate in there somewhere. But it’s not like it was a family pack of anything, so what’s the problem?

The problem, according to health expert Prof Tim Spector, is that Britain is a nation of habitual “on-the-go” snackers and that’s making us sluggish and more hungry and putting our health at risk. A packet or crisps here, a couple of biscuits there – it’s the “mindlessness” of our snacking that is creating problems, he says.

Whether it’s on our commute, in our office vending machines, at convenience stores or late at night in front of the TV, we’re constantly exposed to ultra-processed foods (UPFs) like crisps, cereal bars, sweets and biscuits, Prof Spector said.

Examples of other UPF snacks include flapjacks, protein bars, ice creams, fat-free fruit flavoured yoghurts, processed cheese snacks and pastries.

In fact, a quarter of people are eating healthy meals but undoing their benefits with unhealthy snacks, which increases the risk of strokes and cardiovascular disease, research has found. The findings, published in September in the European Journal of Nutrition from King’s College London and ZOE, the personalised nutrition company founded by Spector, looked at the snacking habits of 854 people.

Most people ate two-three snacks a day and a large proportion chose sweets, cookies or brownies, or crisps. That has a negative effect on health measures, such as blood sugar and fat levels, and addressing this could be a simple diet strategy to improve health, the researchers said. 

So is snacking bad now? 

Remember the “little and often” advice presented to dieters circa 2010 as the Holy Grail of eating? Has that now collapsed under the weight of changing dietary trends?

Not exactly. Healthy snacking – if it suits you – can still keep hunger at bay and blood sugar stable if you plan wisely. 

“The quality of the snacks we eat is the main issue, followed by the mindlessness of how we eat them. We are constantly exposed to UPFs through food advertising and availability at every corner, which makes it difficult to make healthy choices when we’re on the go,” says Spector. 

“These UPFs can be eaten in seconds and tend to be high in fat, sugar and artificial ingredients that are bad news for our gut microbiome, satiety and overall health.” 

How snacking is making you hungrier 

Make the wrong choice when you snack and you can end up even hungrier than before, says Alison Clark, registered dietitian and spokesperson for the British Dietetic Association. 

“Refined carbs and UPF snack foods have a high glycaemic index [GI], which means they break down quickly and glucose from them goes into our bloodstream and peaks within 30 minutes,” she says. As well as UPFs, unexpected foods with high GI include jacket potatoes, ripe bananas and satsumas.

“But straight after that you get a drop to lower than your baseline so within less than two hours you’re hungrier than you were before. It’s that dip that makes you want more of the same that leaves you on a roller coaster of energy highs and lows and cravings.”

And if it feels like you can’t resist that unhealthy snack, you’re right. UPFs have addictive qualities, which explains why we want more of them. 

According to a systematic review of the research in the British Medical Journal about 14 per cent of adults across the world are addicted to food and UPFs play the biggest part in this. 

“The combination of refined carbs and fats found in UPFs seems to have a supra-addictive effect on brain reward systems, which may increase the addictive potential of these foods,” the researchers wrote.  

“Refined carbohydrates and fats can trigger dopamine release in the brain’s striatum, akin to addictive substances like nicotine and alcohol,” says Robert Hobson, a registered nutritionist and author of new book Unprocess Your Life: Break Free From Ultra Processed Foods for Good (Thorson’s, £18.99, out January 2024).

So, how can we optimise our eating so we don’t want to eat all those unhealthy snacks? 

Figure out your food pattern 

“There are different types of people – some that do well on three balanced meals, others that need a healthy snack in between their main meals,” says Clark. 

But how can you know which you are?  

“Try keeping a hunger and snack diary for a week,” she advises. “Write down your hunger on a scale of 1-10 (see box) and by all means snack when you’re at a 3-4, if you’re genuinely hungry. If you’re not, don’t. 

“If you do snack, write down how you feel immediately after and also after a couple of hours. How long before you were hungry again? That will help you understand the snacks that keep you full and those that make you hungrier and let you identify your craving times so you can plan healthy snacks for them. These are likely to be 3.30-4pm when your blood sugar levels naturally dip. 

“When you know your optimum snack times, plan healthy snacks and then log another week to see how they make you feel,” says Clark. See box for ideas.

Hack your breakfast 

“Consider a high-protein low-carb meal in the morning to help regulate blood sugar levels,” says Hobson. 

“In the early hours, blood sugar levels typically start to rise, which is known as the ‘dawn phenomenon’ and occurs due to the release of hormones like cortisol and adrenaline, which prepare the body for the day ahead by increasing the availability of glucose or energy. 

“A sugary breakfast will spike it even more and could lead to a more dramatic crash, so choose a protein and high-fibre breakfast to give you a better balance of blood sugar.” 

He suggests scrambled egg or tofu with avocado on a slice of high fibre rye bread or old-fashioned rolled oats made with milk or milk alternative served with berries, nuts and Greek yoghurt.  

Build your meals to keep you full

The quality of your meals will determine how you feel between them, says Clark. 

Make sure each meal contains a source of low GI carbs (basmati rice, sweet potato, wholemeal, sourdough or rye bread, rice cakes, oat cakes or wholegrains) that break down slowly, an adequate amount of protein (lean meat, fish, tofu, pulses, poultry or eggs) for satiety, fibre (vegetables and fruit) and a small amount of healthy fats (olive oil, olives, nuts and seeds, nut butter or butter). 

“That’s the mix you need to stay fuller for longer and feel satisfied after eating,” she says. “Make sure all your meals are built with all these elements to reduce the desire to snack later on.”  You can build your perfect snack with these elements too.

Put protein first

Protein is “thermogenic”, which means it requires the body to expend more energy digesting it than it would with other, more processed foods. That makes you less likely to feel hungry after a protein-based meal. But eating it before the other food on your plate might also help keep you full too.

“Protein is a key factor in keeping us feeling fuller for longer, as well as being vital for energy, hormone regulation, and the repair of tissues,” says Dr Claudia Ashton, a London GP, nutritionist and head of clinical services at the Roczen weight and diabetes management app. 

“Ideally, protein should be consumed at every meal. Research has also shown that the order in which you eat the different foods on your plate can be significant. For example, having protein and vegetables before carbohydrates in a meal can lead to lower post-meal blood glucose and insulin levels,” she explains. 

Avoid grazing

“Our bodies are not designed to constantly graze,” says Prof Spector. “It can mean that we never give our gut microbes and digestion a well-earned rest, and it can also be more difficult to monitor how much you’re eating in a day.” 

Plus, the constant intake of food leads to repeated blood sugar spikes, which can make you hungrier and also lead to insulin resistance, where your body becomes less adept at using insulin to process glucose and lead over time to Type-2 diabetes, Dr Ashton says. 

“It could take 3-4 hours to digest a balanced meal of, for example, oily fish with wholegrain rice and avocado, which contains good fats, protein and fibre,” says Rob Hobson.  People differ of course, but expect to be hungry about three hours after eating a balanced meal, he advises. 

Choose your fruit wisely

It’s easy to think of fruit as a virtuous option, but it is not always the perfect snack food. 

“Not all fruit is created equal when it comes to snacking,” says Dr Ashton. “In fact, some fruit has a relatively high amount of carbohydrates, which are broken down by the body into sugar. 

“Fruits like satsumas have more fast acting sugars, which can spike blood sugar levels, leaving us feeling hungrier when they come back down. 

“Yellow bananas are also processed differently than their green counterparts, as the ripe fruit contains more sugar. 

“Berries, however, are an excellent choice of snack, particularly when combined with a protein source like Greek yoghurt or good quality nut butter. 

“They don’t have the same spiking effect on blood sugar, they provide natural sweetness, and when combined with protein sources will help to keep you fuller for longer.”  

Stop eating for 10 hours after dinner

If you do nothing else to change your eating – stop snacking at night. In the ZOE research, a third of people liked to snack in the evening. But late-night snacking after 9pm was associated with poor cardiometabolic health, even when that snacking was healthy. 

In fact, all the experts The Telegraph spoke to for this feature pointed to the mounting evidence for keeping your eating contained to a specific window of time in the day as a shortcut to better health, more energy and less daytime hunger. This could mean stopping at 7pm or 8pm after dinner and then not starting again until breakfast the next morning. 

There are various models of intermittent fasting or time-restricted eating ranging from fasting for 12 hours after dinner and eating for 12 hours (12:12) the next day, to fasting for 16 hours and eating for eight (16:8), to fasting for 14 and eating for 10 (14:10). 

New research, also from ZOE presented this month at the European Nutrition Conference has found that fasting for 14 hours after dinner and eating within a 10-hour window the next day – so if you eat your first bite at 9am you should have your last by 7pm – could lead to increased energy, improved mood, as well as improved gut health. 

Build your own smart snack

Choose one option from each of the following categories to create a nutritious snack.

Low GI carbs

Options: Two oat cakes, three rice cakes, one apple/pear, 150g berries, carrot/celery sticks, a cup of green vegetables, slice of wholemeal/rye/sourdough toast

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Protein

Options: Small tub Greek yoghurt, 100g chicken/turkey, half a tin pulses, two hard boiled eggs, a small tin of tuna

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Healthy fats

Options: tbsp hummus, tbsp nut butter, 10 olives, 30g nuts (23 almonds, 49 shelled pistachios and four to six Brazil nuts)

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Healthy snack