Thanks to celebrity endorsements from Gwyneth Paltrow and Miranda Kerr, lemon-infused water is gaining notoriety as a drink that helps weight loss.
The spiked water supposedly flushes toxins from the system, reduces appetite, and alters the body’s digestive processes to block fat absorption.
And that all sounds excellent for weight loss – if lemon water worked that way. The problem with lemon-infused water is it doesn’t include the most effective part of the fruit (in terms of weight management, that is).
Initial hype stems from a 2008 Japanese study that linked lemon’s polyphenols – micronutrients with antioxidant properties – to less weight gain, and improved metabolism in mice on high-fat diets. The research team concluded that it was feasible that these lemon polyphenols may stimulate the liver to create enzymes which block fat absorption.
Having said that, that research was done on mice. There’s still no comprehensive studies on lemon water and its ‘beneficial’ effects on humans.
The other issue, which we alluded to earlier, is that lemon water employs the lemon’s juice, rather than the coveted rinds. Mice in the study were eating a diet loaded with lemon rind, which holds the majority of the polyphenols in lemons. Some people may include rind-and-all in their lemon-infused water, but it’s probably nowhere close to the magnitude of the mice’s consumption.
And even if you did commit to a heavy-rind-and-water diet, the acidity in a lemon-heavy diet could do some serious corrosion to your teeth.
In moderation, lemons are a solid source of vitamin C; some studies have linked low vitamin-C status to obesity. But it’s a stretch to say vitamin C alone can prevent or reverse weight gain. Pectin, a form of fiber in lemons, has been linked to similar weight loss effects.
“Pectin can lower LDL or bad cholesterol and has some anti-inflammatory benefits,” says Bahram Arjmandi, a professor of nutrition at Florida State University and editor-in-chief of the Journal of Food and Nutritional Disorders.
“It can also prevent fat absorption and moderate insulin response.”
But similar to polyphenols, that elusive pectin isn’t found in the fruit’s juice.
“You’d have to eat a whole lot of lemon to see these benefits,” Arjmandi continued. “It’s hard for me to imagine that being practical.”
“Lemon water is not a miracle weight-loss food,” adds Elizabeth Dejulius, a registered dietitian nutritionist with Cleveland Clinic.
Miracle weight loss aspirations aside, lemon water can indirectly help people slim down. Thirst is often mistaken for hunger, though most find water ‘boring’; they may as well eat. Adding lemon, however, cuts dehydration, in turn reducing thirst-triggered food cravings.
Related: The Health Benefits of Lemon Water
“Dehydration can also slow metabolism, which in the long-term can lead to weight gain,” Dejulius says.
The power of a placebo effect could also have a say, too.
“If your mind believes strongly that drinking lemon water does something, like suppresses appetite, maybe it will,” Arjmandi says. “This kind of placebo effect is always a possibility.”
Taking everything in consideration, if you’re already drinking lemon water, you should continue doing so (especially if you’re sipping it as an alternative to sugary sodas). But if you’re a person who needs that scientific evidence in your weight loss plan, you’ll need to adapt another area of your diet.