Can fluid intake curb hunger?

Amy Wood - Nutritionist | 24 Oct, 2021

If constantly feeling hungry is making it difficult for you to stick to your calorie allowance, it's possible your fluid intake could be the culprit!

Mixed messages

Our brains sometimes have trouble distinguishing between thirst and hunger, often confusing the need for a drink with a desire to eat. Mild dehydration is easily perceived to be hunger, meaning we reach for a snack when really, we just need a drink.

The next time you're feeling peckish for a snack, first try having a glass of water, and then waiting 15 minutes. If you're still hungry after that, you know you are genuinely hungry. If you find you feel satisfied after the water, you'll know you were just thirsty all along!

Some studies have also shown that water can supress appetite. By filling the stomach with liquid, we leave less room for food, so require smaller portions than usual to feel full – generally resulting in a lower calorie intake. This evidence is specifically observed in those eating with the intention of losing or maintaining weight (the vast majority of Nutracheck members!). Try it out for yourself and see if you notice a difference! Drink a glass or two of water before each meal for a couple of days and see how your feelings of fullness change. Hopefully, you find a smaller portion does the trick, and you find it easier to stick to your calorie target.

Super soups!

Soups are also a great option for satisfying both hunger and thirst in one sitting. The high water content of soup is hydrating, while the inclusion of meat, beans and/or vegetables helps to fill us up and provide essential nutrients.

Top tip! Blended soups tend to keep us feeling fuller for longer compared to broth type soups. This is because they take longer to pass through the stomach and be digested. Imagine pouring a minestrone-type soup through a sieve – the liquid will pass straight through, leaving the veg and pasta in the sieve. However, if you were to put this soup through a blender and then pour it into a sieve, it now takes a lot longer to pass through. Combining the liquid with solid food creates a more substantial mix that takes longer to be digested.

Just watch out for the salt in shop-bought soups – some can contain up to half of our daily recommended limit in just one tin!

Sparkling or still?

To make water more interesting, some of us prefer sparkling instead of still. While adding fizz to water doesn't add any calories, there is some evidence to suggest it may contribute to cravings. Clinical trials have suggested that carbon dioxide, which gives fizzy drinks their 'fizz', may stimulate receptors in stomach cells to release a hormone called ghrelin, which increases feelings of hunger. This may lead to an increase in calories consumed in the meal following the drink. The carbon dioxide that gives fizzy drinks their 'fizz' may stimulate receptors in stomach cells to release ghrelin, which increases feelings of hunger.

Diet drinks: are they really a better choice for our waistlines?

Replacing sugar-sweetened beverages with 'diet' alternatives is an attractive prospect, however it doesn't necessarily mean they are as good as water. Looking deeper into the effects of sweeteners in the body, we see some evidence that the sweetness, despite being zero calories, still partially activates the food reward pathways in the brain that makes us feel good when we eat. This means sweeteners may contribute to further cravings for sweetness. The more we taste sweet flavours, the greater the intensity of sweet flavour we need to satisfy our cravings (often meaning more sugar!).

So while diet drinks are a better choice for our dental health and should help us stick to our calorie allowance much easier than if we were to have sugar-laden versions – it's worth paying some attention to the effects they may be having on your sweet tooth and craving.

Don't ignore true hunger!

The evidence that water may supress appetite doesn't mean we should be ignoring our body signals. If you feel hungry, and a glass of water doesn't cut it, that means your body really does need food – grab a healthy snack or take that as your signal that it's time for a meal. It's really important not to deny yourself of food – listening to your hunger cues is the key to maintaining a healthy relationship with food and ensuring your body is fuelled to work at its best.

Nutritionist Amy Wood (ANutr), MSci BSc Nutrition has a keen interest in the relationship between diet and health. Having been published in the European Journal of Nutrition, Amy is passionate about making evidence-based nutrition accessible to everyone and helping others to adopt a food-focused approach to taking control of their health.