Could the order in which you eat certain foods – rather than the amount – be the key to staying slim and healthy?
That’s the claim behind the latest TikTok diet craze, known as ‘food sequencing’, with wellness influencers sharing videos of themselves eating a bowl of salad or veg before their dinner, or nibbling a handful of protein-rich nuts before a meal containing carbohydrates (eg rice or pasta).
They claim that separating food groups and eating them in a particular order can help you stop unnecessary snacking, lose weight – and even reduce symptoms of conditions such as polycystic ovary syndrome, or PCOS, where hormonal disruption triggers weight gain, irregular periods, excess hair and poor control of blood sugar levels.
But is there any science to back these claims?
Researchers at Imperial College London found that eating a sugary dessert first resulted in people eating less at their next meal
Dietitian Clare Thornton-Woodome studies have found that food sequencing can reduce overall calorie intake
There’s actually nothing new about the idea that eating foods in a certain order could be beneficial. In fact, sequencing formed the basis of the Hay diet – invented by US doctor Dr William Hay in the 1920s and which became popular again in the 1990s when a wave of celebrities including Elizabeth Hurley revealed they followed it.
Hay encouraged people to never eat carbs and protein at the same meal, but to separate them out by several hours and to only have fruit for breakfast, claiming this would avoid digestion problems and boost general health.
Hay’s diet was based on the idea that some foods were alkaline and others acid and the two should never mix. Although science has debunked these theories, could Hay have been on to something without realising why?
‘Some studies have found that food sequencing can reduce overall calorie intake,’ says Guildford-based dietitian Clare Thornton-Wood.
In fact, researchers first showed this 20 years ago – a 2004 study by Pennsylvania State University in the US found that when people ate a salad starter before their main meal, they ate around 12 per cent fewer calories overall, while 2007 research by the same university found that eating a bowl of chunky vegetable soup first reduced overall calorie intake by 20 per cent.
More recently, researchers at Imperial College London found that eating a sugary dessert first resulted in people eating less at their next meal. The 2014 study looked specifically at a brain protein called glucokinase which keeps track of how much sugar is eaten – as sugar is the brain’s main fuel source, this protein will tell the body to find more if the intake is too low.
So, in theory, by eating sugary food first the brain quickly determines enough has been eaten, allowing other bodily systems we have that control appetite to kick in and stop us from overeating. Whereas if sugary foods are eaten in smaller amounts throughout or after a meal – as dessert normally is – the fullness trigger is activated later and you end up eating more overall.
‘It’s an interesting study, but I wouldn’t suggest eating pudding first based on it,’ says Clare Thornton-Wood, ‘It could backfire and mean people fill up too much on a sweet treat that has very little nutritional value and then are too full to eat their main meal, missing out on vital nutrients such as protein, and the fibre and vitamins found in vegetables. Eating lots of sugary foods can also just make some people crave more as it activates key pleasure centres in the brain.’
However, as well as appetite suppression, the supposed benefits of food sequencing as espoused on TikTok is often attributed to its effect on your blood sugar levels – stable blood sugar levels are linked to fewer food cravings, reduced weight gain and, long-term, a lower risk of type 2 diabetes and heart disease.
The logic here is that foods cause a more dramatic spike in blood sugar depending on what food comes before or after them – and there is some research to back this up.
A study at Kanazawa University in Japan in 2018 found that eating protein (in the form of meat) or vegetables before rice could reduce blood sugar spikes. The participants who ate rice at the end of the meal had a significantly lower increase in blood sugar and insulin levels 30 minutes later than those who consumed rice first.
‘What we call “preload” studies, where people are given a particular nutrient or food up to 30 minutes before a meal, show that consuming protein, fat or fibre before a carbohydrate-rich meal can reduce glucose spikes,’ says Professor Sarah Berry, a nutritional scientist at King’s College London and chief scientist at Zoe, the nutrition app, who has led research into the effects of different foods on blood sugar.
‘This is because they slow gastric emptying [how quickly food is digested] and also because protein stimulates insulin release, which means that as the carbohydrate enters the bloodstream, it’s removed more quickly, hence the lowering of the blood sugar response.’
So should we all plump for eating either some protein, fat or veggies before we eat anything carb-rich, such as pasta or rice? ‘Generally speaking, having a high-protein preload or a high-fibre preload prior to consuming a carbohydrate-rich meal will mean you get less of a blood sugar spike,’ says Professor Berry. ‘And this better blood sugar control could potentially benefit metabolic conditions such as PCOS and prediabetes. But importantly, this doesn’t happen for everyone and not in every study, so it isn’t a one-size-fits-all strategy,’ she continues.
And what about the studies showing that the continental custom of salad or soup before your main meal can reduce your overall calorie intake? ‘Salads and soups are generally high in fibre, which is bulky and can help you feel fuller, so when your main meal arrives you’re probably less ravenous and eat a bit less,’ says Professor Berry.
Salads and soups are generally high in fibre, which is bulky and can help you feel fuller if you eat them first
‘We also know high-fibre foods slow how quickly food moves through your gut, which in turn slows down glucose absorption into your blood, thereby reducing your blood sugar response after eating.’
And there’s some evidence that food sequencing may be helpful if someone has a medical need to improve blood sugar control.
For example, in a small 2023 study of 40 people whose blood sugar levels classified them as at-risk of diabetes (prediabetes), half were advised to eat the carbohydrate portion of their meal last – after the protein and vegetables – for 16 weeks, compared with standard healthy eating advice. While both groups lost weight and improved their blood-sugar readings, the carbohydrate-last group significantly increased their vegetable intake and also found the approach easier to stick to – and were more likely to say they’d continue to eat this way.
The researchers, writing in the journal Nutrients, suggested this approach could be more practical for people with prediabetes than, for example, low-carb diets, which can be difficult to stick to.
‘But it’s also key to remember that micro-managing glucose spikes by food sequencing just isn’t necessary for most of us and will only actually have a small impact on blood sugar management,’ adds Professor Berry.
‘We don’t want to pathologise having a glucose increase after a meal. It’s normal. Our bodies are well equipped to handle it. We should focus more on getting a balance of good foods in a meal rather than the order in which we eat them.’
Dietitian Clare Thornton-Wood agrees: ‘Instead of carefully separating and ordering when we eat different foods – which can be triggering for people with disordered eating issues – it’s much more important to get decent levels of all the important food groups.
‘Aim for at least five portions of fruit and veg per day, a protein source at each meal, a portion of carbohydrate (ideally wholegrain) and three servings of dairy or plant-based fortified alternatives each day and you’re giving your body the best ingredients to achieve a healthy weight and keep yourself fit and well.’
