Weight loss: Drinking a gallon of water a day probably won’t help you shed kilos

ISLAMABAD: It’s often claimed that if you’re trying to lose weight, one of the things you should do each day is drink plenty of water – with some internet advice even suggesting this should be as much as a gallon (about 4.5 litres).

The claim is that water helps burn calories and reduce appetite, which in turn leads to weight loss.

 But while we all might wish it was this easy to lose weight, unfortunately there’s little evidence to back up these claims.

 One small study, of 14 young adults, found drinking 500ml of water increased resting energy expenditure (the amount of calories our body burns before exercise) by about 24 per cent.

 While this may sound great, this effect only lasted an hour. And this wouldn’t translate to a big difference at all. For an average 70 kg adult, they would only use an additional 20 calories – a quarter of a biscuit – for every 500ml of water they drank.

 Another study of eight young adults only saw an increase in energy expenditure when the water was fridge cold – reporting a very modest 4 per cent increase in calories burned.

This may be because the body needs to use more energy in order to bring the water up to body temperature, or because it requires more energy for the body to filter the increased volume of fluid through the kidneys. And again, this effect was only seen for about an hour.

Pink up your pout this summer

So although scientifically it might be possible, the actual net increase in calories burned is tiny. For example, even if you drank an extra 1.5l of water per day, it would save fewer calories than you’d get in a slice of bread.

It’s also worth noting that all this research was in young healthy adults. More research is needed to see whether this effect is also seen in other groups (such as middle-aged and older adults).

Even more interestingly, due to the stomach’s shape, fluids can bypass any semi-solid food content that’s being digested in the lower part of the stomach.

This means that water can still be quickly emptied from the stomach. So even if it’s consumed at the end of a meal it might not necessarily extend your feelings of fullness.

If you’re trying to eat less and lose weight, drinking excessive amounts of water may not be a great solution. But there is evidence showing when water is mixed with other substances (such as fibre, soups or vegetable sauces) this can delay how fast the stomach empties its contents – meaning you feel fuller longer.

But while water may not help you lose weight directly, it may still aid in weight loss given it’s the healthiest drink we can choose.

Swapping high-calorie drinks such as soda  for water may be an easy way of reducing the calories you consume daily, which may help with weight loss.