Can volume eating really help with weight loss? What the science says

Trigger warning: This article discusses weight loss which may be triggering to those at risk of disordered eating. If you are concerned, help and support is available.

Enormous salads, towering vegetable bowls and giant low-calorie meals are taking over social media feeds.

Known as volume eating, the approach claims that eating very large portions of low-calorie foods can help you lose weight without struggling with hunger. But does it stack up scientifically, and are there any risks?

Volume eating is about building big meals from foods that are rich in water and fibre. For example, fruits and non-starchy vegetables like carrots, cabbage, cucumber, green beans and berries.

These tend to be combined with lean proteins like chicken and smaller portions of grains.

Because these ingredients are low in calories, the idea is you can eat extra large portions – think mixing-bowl size.

Volume eaters share recipes like fajita chicken cucumber salad and pad Thai salad with 300–400 calories and 30–40g of protein, despite looking like a much larger meal.

The main reason people choose to volume eat is for weight loss, as some think it feels easier and more manageable.

Weight loss is often simplified to 'eat fewer calories', but the physiological response to this is an uptick in hunger, external and a drop in fullness after eating, making it harder to stick with a diet over time.

Volume eating tries to outsmart the biological drive to maintain energy intake.

Rather than focus on eating 'less', the idea is to eat more by choosing foods that provide plenty of volume for relatively few calories. This helps dieters feel full and satisfied with less energy intake.

Volume eating also appeals to people looking to maintain their weight, which can be equally challenging as the body adapts to weight loss in ways that can drive weight regain, external.

Much of the science, external behind volume eating comes from the work of nutrition researcher Barbara Rolls. Her research in the 90s showed that changing the energy density of meals – by adding water, broth, vegetables and fruit – meant participants ate fewer calories without reducing how full they felt.

Her later research, alongside that of other researchers, found most people tend to eat a relatively consistent weight of food each day, regardless of its calorie or macronutrient content.

So, if more of the food is lower in energy density, people can consume fewer calories without feeling hungrier.

Since then, research has confirmed that lower-energy-dense diets can help manage hunger and appetite, external during weight loss and are associated with lower energy intake and body weight, external.

Approached sensibly, it can be.

Roughly 45% of adults, external are trying to lose weight, but maintaining weight loss can be challenging, both because of the food environment and because the body adapts to weight loss in ways that can drive weight regain.

At the same time, most adults are not eating, external five portions of fruit and vegetables a day or the recommended 30g of fibre.

So, if a volume eating approach helps someone on a weight loss journey to eat more fruit, vegetables and fibre, there can be nutritional benefits too.

Lower energy dense diets have been linked with higher nutrient intake, external and better health outcomes.

Volume eating isn't for everyone and as with most diets, there are potential side effects.

One is gut distress. Volume eating can push fibre intake to over 50 grams a day, which can cause digestive symptoms like bloating, gas and tummy pain.

A sudden increase in fibre without enough fluid can also cause constipation as stools become hard and bulky. If your diet was previously low in fibre (or you have a gut condition like IBS), the effects can be more pronounced.

If you notice this, pull back on the amount of vegetables (particularly raw), and switch up the grains for refined versions to help ease symptoms.

This could cause under fuelling. If you have an active lifestyle or train regularly (particularly if you play sport or do frequent gym workouts), low-calorie volume eating is unlikely to provide you with enough energy (and particularly carbohydrate) to meet both your body's daily needs and fuel your training.

In some cases, this could lead to a state known as low energy availability (LEA), external.

In the short term, symptoms can include fatigue, brain fog, poor recovery and struggling with workouts.

These are warning signs that shouldn't be ignored. If prolonged, LEA becomes increasingly detrimental to health, and can lead to low mood, injuries, disrupted hormones, poor bone health and missed periods.

For some people, volume eating could also lead to disordered eating behaviours.

A number of eating disorder researchers have looked into the concept of 'volume-addiction', external, which is an emerging concern.

It's a pattern of compulsive, fullness-seeking eating. Although not yet fully studied, the driver appears psychological: because stretch receptors in the gut communicate with reward centres in the brain, the sensation of fullness can soothe or provide a sense of calm, external.

These neural networks show plasticity, so over time it may take more food to achieve the same response.

There are elements of volume eating that are positive. Building meals around fruits, vegetables, wholegrains, pulses and lean proteins like tuna, tofu and pulses is in line with current healthy eating advice.

Eating more fibre-rich foods that are low in energy density can help you feel full, so if you're trying to lose weight, this is a useful strategy.

If you're active, remember that carbohydrates are essential for fuelling your body's normal function and training.

So, prioritise grains, fruit and starchy veg like sweet potato in your meals as well as vegetables.

And remember, fullness is influenced by more than volume. Protein, texture and timing can also affect appetite.

Avoid a volume eating approach if you have previously experienced an eating disorder. If you recognise any of the warning signs discussed above – or begin feeling fearful of eating higher-calorie foods, speak to your GP.

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