London - When you think about it it's odd that Instagram - no more than an online photo sharing platform - has become a go-to-place for advice on healthy living.
But here we are, basing our dinners on photos of kale smoothies and quinoa salads made by people who don't have any qualifications and that we'll never even meet.
Tap “#health” into Instagram, and it's not long before you stumble across a photo of what is ceremoniously called a “detox drink” consisting of a seemingly random piece of fruit, often a lemon, floating in a jug of water. A quick Google and such drinks are lauded as having 'fat burning properties' and the ability to alkalise your body - whatever that means.
On the offset, putting a piece of fruit in water has no obvious benefits other than making it more refreshing. Yet such is the power of the Juno Instagram filter: bathing everything in an irresistible glow.
But it begs the questions: the people in the photos seem so healthy and fit and generally better at life - surely there must be something in the, er, water? Can lemon-infused water really cut through body fat? The resounding answer from experts is no. The only way to melt away harmful fat is by creating a negative balance of energy in the body. This is achieved by burning more calories than you consume.
Professor Jimmy Bell of the Life Sciences department at the University of Westminster explains that the concept of fat burning when the body utilises fat as an energy source, instead of carbohydrates, does exist.
A photo posted by •A• (@on.my.minddd) on May 25, 2016 at 3:44am PDT
But he warns the concept is misused by the diet industry to convince self-conscious dieters that some compounds can attack fat. Highlighting how such claims can lead people to buy useless, and sometimes dangerous, “fat burning” products online, he stresses: “the truth is that none have been clinically proven to actually work.”
Some animal and lab studies have shown that certain foods, such as chickpeas and lentils, can affect the appetite and digestion by fermenting in the colon. This could in turn encourage the body to use its fat stores.
However, such mechanisms haven't been proven in robust human trials, he explains. “Most of the research has been done in cellular systems and in smaller groups studies that have been shown to take place in animal models in large quantities.”
As for lemon and fruit-infused water, he says no trials have proven that it can, or can't, burn fat.
“I can't think of a mechanism where lemon water would have an effect on body fat” he says.
Dr Yvonne Jeanes RD, Senior Lecturer in the department of Life Sciences at the University of Roehampton, concurs, and cautions against the notion of “detox” foods.
“The body has its own excellent mechanisms to get rid of toxins and waste [involving] organs such as the gastro-intestinal tract, the liver and the kidneys.
Dr Bell agrees: “So-called detox foods to counterbalance a toxic diet won't work. A detox food is not like water to fire. If you want to 'detox' yourself stop eating rubbish -you don't need 'detox' food.
“We want to eat what we want with no consequences and think that 'detox' will clear all the problems, but that won't happen. Staying healthy is a lifetime struggle.”
The take away message is then, that while drinking lemon or fruit-infused water isn't harmful, it won't have a significant impact on your health.
“If adding fruit and vegetables makes the water taste nicer, it could encourage people to drink more and stay hydrated. It can also add some nutrients, such as vitamin C,” says Dr Sue Reeves, Sue Reeves, Principal Lecturer in the department of Life Sciences at the University of Roehampton.
“The most important thing to consider when trying to achieve or maintain a healthy body weight is to look at overall calorie intake, taking particular care in looking for hidden sugars in food, like ketchup and savoury foods, where you might not expect them,” says Dr Jeanes.
“Another good example of hidden sugars is lemon-flavoured desserts, which often have extra sugar needed to sweeten them. And above all, be sure to eat adequate amounts of fruits and vegetables.”
Dr Bell has some franker advice when asked whether there is any significant benefit from putting fruit in water.
“Scientifically no, but it tastes very nice. If you spend all day drinking lemon water it stops you from eating because you're doing something else, you could be chewing gum for that matter.
He adds: “You're better off going to the gym.”
The Independent