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If you are craving a satisfying dish but trying to be careful about you weight, few things are more dispiriting than reading the “healthy” options on a food menu. Words like “light”, “wholesome”, “skinnylicious”, “sensible”, “mild” – the adjectives that often accompany low-fat, low-carb options – hardly prepare you for a pleasurable meal.

One obvious consequence is that it makes the foods seem less desirable, so you may be more tempted by indulgent choices: the “rich”, “flavourful”, “delicious” dishes. But the influence of these words can stretch far beyond our immediate decision-making.

The way we think about food can powerfully influence our satiety long after we have finished eating, and thanks to the mind-body connection, it can even shape our hormonal responses and the meal’s passage through the gut. As a result, our expectations around food can determine whether we will experience greater hunger pangs afterwards and find it harder to resist snacking later in the day. And this is all down to the sense of deprivation created by the way the food was described, irrespective of the number of calories actually consumed.

No wonder dieting is often so agonising: our culture has led us to associate healthy eating with greater hunger, and that becomes a self-fulfilling prophecy. Fortunately, as I describe in my book The Expectation Effect, there are many ways to change our food mindsets, and they all centre on the idea that pleasure is an essential ingredient for any weight-loss regime. As paradoxical as it may seem, cultivating an indulgent attitude to food may be the best way to control your waistline.

It was a man called Henry Molaison who provided some of the first clues to the ways our mind can influence our appetite. In the early 1950s, Molaison underwent experimental brain surgery to treat epilepsy, but the operation caused irretrievable damage to his hippocampus. , he could no longer form new memories, leading him to live in the “permanent present tense”, in the words of the neuroscientist Suzanne Corkin.

. They revealed, for example, that we can learn skills unconsciously without being able to recall the lessons themselves.

, however, is Molaison’s seemingly bottomless stomach. In the 1980s, Nancy Hebben at Harvard University asked him to rate his satiation on a scale from 0 (famished) to 100 (completely full) before and after his meals. If appetite were mostly directed by signals from the stomach, you would have expected Molaison’s ratings to have risen after his meals. Yet they barely shifted.

To test whether his memory deficit would change his eating behaviour, the scientists performed a dinner-time experiment. After he had finished his meal, they cleared the table, and, within a minute, offered another plate of food. Amazingly, he ate nearly all of it – and, despite having consumed almost twice as much as normal, he reported only a moderate increase in his satiety.

How could this be? There is little doubt that appetite is influenced by “bottom-up” signals in the digestive system, such as a feeling of stretch in the muscles of the gastrointestinal tract, and feedback from chemical sensors that can detect the presence of nutrients. The experiences of people with amnesia like Molaison, however, suggest that we also rely on “top-down” sources of information – such as our memories of what we have eaten – to make sense of those cues, create the overall feelings of satiety and hunger, and to control subsequent food intake.

Amnesia may offer extreme examples of these processes in action, but further research has shown that we are all susceptible to top-down influences on our appetite. , while prompts to recall a previous meal curb people’s snacking.

, Suzanne Higgs at the University of Birmingham, UK, invited a group of students into her lab to perform a taste test on some cookies, which, after completing a couple of questionnaires, they were free to consume. Higgs found that prompting the subjects to remember their lunch, by spending a few minutes describing what they had eaten, caused them to eat about 45 per cent less – around four cookies – than participants who wrote about their general thoughts and feelings, rather than their meal memory. This wasn’t the case for participants who wrote about a meal from the day before – a more distant event that would have little effect on their feelings of satiety in the moment. Instead, it was expectations of current satiety, based on the recent memory, that mattered.

Mind over menu

Aside from memory, other contextual factors seem to shape our expectations of satiety, including the information we are given about a meal’s contents. Researchers at the University of Aberdeen, UK, invited 26 people for an omelette breakfast on two occasions. Before they ate, participants were shown the ingredients. This was, ostensibly, to check whether they had any allergies – but the real purpose was to change their expectations. On one occasion, they were shown two eggs and 30 grams of cheese; on the other, they were shown four eggs and 60 grams of cheese.

In reality, the participants all ate the same portions – three eggs and 45 grams of cheese – for both breakfasts. . People who had seen the smaller pile of ingredients subsequently ate more pasta from a buffet at lunchtime than those who believed they had already consumed a hearty meal.

. In another small study, participants who thought they had consumed a large quantity of blitzed fruit tended to be less hungry over the following 3 hours than those who had seen a smaller portion.

Of course, we don’t always get to see the original ingredients in meals, especially in ready-made food, but labelling can influence our appetite through similar mechanisms. Many people associate the word “healthy” with “unfulfilling”, for instance, which reduces their expected satiety (see “What’s your food mindset?“). , they subsequently felt hungrier than people who had eaten the same bar when it was labelled “tasty”. Indeed, the association was so strong that they felt hungrier than people who had eaten nothing at all.

It is easy to assume that these effects are simply a subjective assessment of our hunger based on what we think we have eaten, a trick of the mind that leads us to consume more. But remarkably, these expectation effects also alter our physiological responses to food. Of particular interest in this field is the “hunger hormone” ghrelin, levels of which tend to rise before a meal and drop straight after. The higher its levels, the stronger the urge to eat.

In the early 2010s, Alia Crum, now at Stanford University in California, invited 46 participants into the lab on two occasions to try out different recipes for a shake. One was labelled in big letters as “Indulgence: decadence you deserve”. The accompanying description emphasised the “smooth, rich and delicious” flavours and textures, and on the nutritional information, it claimed 620 calories in total (270 of which came from fat). The other was called a Sensi-Shake. It was “light”, “sensible” and offered “guilt-free satisfaction” in only 140 calories. In reality, the shakes on both days were exactly the same, containing 380 calories each.

To measure people’s ghrelin responses to these manufactured expectations, Crum’s team took blood samples at regular intervals before and after people read the marketing material, and after they had drunk the shakes. For the indulgent shake, the ghrelin levels changed exactly as you would hope after a meal, dropping in line with the expected effects on their hunger. , however, the ghrelin levels barely changed at all.

Since then, further studies have shown that our expectations of satiety can also influence , which suppresses appetite. Given that ghrelin and GLP-1 can both bind to neurons in the hypothalamus, it shouldn’t be surprising that expected satiety correlates with activity in this key brain region, which is known to control the body’s overall energy intake and expenditure.

No more ‘light’n’low’

Our expectations can affect , too. In , participants were told that a cherry-coloured drink would turn to solid in their stomach. The manipulation seemed to shift the participants’ expected satiety, with one saying that “I feel like I swallowed a rock!” Using a chemical tracker in the drinks, the researchers found that the food then took longer to travel from the mouth to the large intestine – which may have contributed to their sense of fullness. And participants ate less later in the day than those who believed, rightly, that the drink had remained a liquid.

We don’t yet know the full consequences of our food mindsets, besides their role in shaping appetite. But it is possible that these hormonal and neurological changes also determine how quickly the body burns calories or stores them as fat. If so, they could affect our weight.

Restaurateurs and food manufacturers should take note of these findings and change the way they frame health foods. As Crum and her colleagues have pointed out, you could easily spice up the descriptions of vegetable dishes, say, with sensual and emotive language that evokes indulgence and enjoyment: “zesty ginger-turmeric sweet potatoes” or “sweet sizzlin’ green beans and crispy shallots” in place of “cholesterol-free sweet potatoes” and “light ‘n’ low-carb green beans and shallots”. , it should also help to ensure the consumer feels fuller for longer.

As we wait for our broader food culture to change, there are plenty of ways that we can start to apply this research ourselves. Many weight-control plans involve some form of calorie restriction, and a number of psychological principles can ease that process.

If you are looking to lose weight, one easy step would be to avoid liquid calories. , even if they have the same calorie content. You may feel fuller after eating pieces of fruit than after drinking a smoothie, for example. High-sugar sports recovery drinks are a particular example of something that contains more calories than your body would expect. , combined with the health-focused labelling, means that these drinks are even less likely to reduce your appetite than solid food, so you may try to make up for the perceived deficit with snacking. The same goes for meal replacement shakes and smoothies that are billed as providing a balanced meal in a drink, and often touted as “light” or “low carb”.

A second step would be to pay more attention to the taste and textures of what you are eating. It can be tempting to think, if you are on a diet, that you have to sacrifice your enjoyment of food, but the research on mindsets shows that excitement and anticipation of meals matters more, not less, if you are trying to lose weight. if you choose foods with more intense flavours and make an effort with the presentation so the meal feels like a treat. According to this research, the very worst thing you can do is to eat something insipid that leaves you feeling deprived, just because it has slightly fewer calories than a more appetising option. You will just want to eat more.

that distract you from the experience of eating. If you watch TV or work during meals, you won’t appreciate the food going into your mouth, and may not even remember how much you have eaten later. As Higgs points out, you may be in a very similar situation to people with amnesia. , but eating slowly and taking care to chew each mouthful can improve the orosensory enjoyment of what you are eating, which can in turn trigger a greater hormonal reaction to the food and leave you feeling fuller for longer.

A sense of indulgence seems equally important if you have a treat. In a Canadian and French study from 2016, researchers first encouraged participants to vividly imagine the taste, smell and texture of various sweet treats. The participants were then asked how much they wanted of a delicious-looking chocolate cake. You might expect that picturing these tasty delights would have increased people’s lust for cake, leading them to opt for a bigger slice. . They were more likely to select a smaller portion than those who hadn’t been primed to think about the sensory qualities. , but various studies have shown that greedily imagining a treat can help people curb their eating.

Ultimately, if you want to reduce how much you are consuming, the aim should be to realise that you can get all the pleasure you need from fewer mouthfuls, so that you choose a small portion and feel less tempted to snack later on. Whether you are eating a salad or a chocolate bar, a sense of celebration will help you to control your calorie intake.

Let’s be clear: you can’t turn a lettuce leaf into a feast with the power of your mind. A crash diet is unlikely to be much easier with these small psychological steps, and they can’t give you carte blanche to eat whatever you like. For regimes that involve a reasonable reduction in calories over a long and sustained period, however, these small mental shifts could certainly help. With the right mindset, we can sometimes have our cake and eat it, and still meet our health goals.

What’s your food mindset?

The way we think about what we eat determines how satisfying we find certain foods, with knock-on effects for our weight.

Consider the following questionnaire. On a scale of 1 (strongly disagree) to 5 (strongly agree), do you think that:

· There is usually a trade-off between the healthiness and tastiness of food

· There is no way to make food healthier without sacrificing taste

· Things that are good for me rarely taste good

between responses to these statements and people’s propensity for weight gain: the more strongly they agree with these three statements, the greater their body mass index tends to be.

In the past, some people might have imagined that this was because of low self-control – they simply didn’t want to give up the pleasure of food. But these kinds of attitudes may create an expectation effect on people’s appetites, so that the mere sight of “healthy” on a food label sets someone up for lower satiety after they have eaten a lower calorie meal (see main story). This would leave them feeling hunger pangs, making dieting much harder.