Lemon water is generally a very low-calorie beverage.
Assuming you squeeze the juice from half a lemon into water, each glass of lemon water will contain just six calories.
For this reason, if you swap out higher-calorie beverages like orange juice and soda for lemon water, then this can be an excellent way to cut calories and help with weight loss.
For example, one cup of orange juice (237 ml) contains 110 calories, and a 16-ounce (0.49-liter) bottle of soda contains 182 calories.
Replacing even just one of these beverages per day with a glass of lemon water could reduce daily calorie intake by 100–200 calories.
Some evidence even shows that drinking low-calorie beverages with meals could decrease the number of overall calories consumed in the meal.
In one study, 44 women ate lunch with either a beverage that contained calories or one that did not. Researchers then measured the calories consumed.
They found that drinking calorie-containing beverages like soda, milk and juice with a meal did not make people compensate by eating less. Instead, the total calories consumed increased, due to the added calories from the beverage.
Though lemon water is not calorie-free, it is low enough in calories that it could produce a similar effect and help decrease calorie intake.
From carrying nutrients to cells to transporting waste out of the body, drinking enough water to stay hydrated is a critical component of health.
Maintaining adequate hydration is essential in everything from regulating body temperature to improving physical performance.
Some evidence also suggests that staying hydrated can aid in weight loss.
Research indicates that increased hydration may increase the breakdown of fats and enhance fat loss.
Staying well-hydrated may also help reduce water retention, which can cause symptoms like bloating, puffiness and weight gain.
Since the majority of lemon water is made up of water, it can help with maintaining adequate hydration.
Studies show that drinking enough water can potentially help increase your metabolism.
Researchers suggest that good hydration enhances the function of mitochondria, a type of organelle found in cells that helps generate energy for the body.
This leads to an increase in metabolism, which may lead to subsequent weight loss.
Drinking water has also been shown to increase metabolism by inducing thermogenesis, a metabolic process in which calories are burned to produce heat.
In one study, 14 participants drank 16.9 ounces (0.5 liters) of water. Drinking water was found to increase their metabolic rate by 30% for 30–40 minutes.
Another study looked at the effects of drinking water in 21 overweight children. Drinking 0.3 ounces of water per 2.2 pounds of body weight (10 ml/kg) increased metabolism by an impressive 25% for 40 minutes.
Research on lemon water specifically is limited. However, because water is the main ingredient, it likely carries the same metabolism-boosting benefits as regular water.
Drinking water is often recommended as a fundamental part of any weight loss regimen, as it can promote satiety and fullness without adding calories.
A 2008 study looked at the effects of water on calorie intake in 24 overweight and obese older adults.
The study revealed that drinking 16.9 ounces (0.5 liters) of water before breakfast decreased the number of calories consumed in the meal by 13%.
Another study found that drinking water with a meal decreased hunger and increased satiety during the meal.
Because lemon water is low in calories and can promote fullness in the same way as regular water, it can be an effective way to help reduce calorie intake.
Due to its potential beneficial effects on metabolism, satiety and hydration, some evidence suggests that water (including lemon water) could enhance weight loss.
In one study, 48 adults were assigned to two diets: a low-calorie diet with 16.9 oz (0.5 liters) of water prior to each meal or a low-calorie diet with no water before meals.
At the end of the 12-week study, participants in the water group had lost 44% more weight than participants in the non-water group.
Other research suggests that increasing water intake could help stimulate weight loss, independent of diet or exercise.
A 2009 study measured water intake in 173 overweight women. It found that greater water intake was associated with a greater loss of body weight and fat over time, regardless of diet or physical activity.
Though these studies focus specifically on regular water, the same results most likely apply to lemon water as well.
Lemon water comes with a lot of potential benefits, from promoting hydration to increasing satiety.
However, it’s important to note that these benefits all come from its main ingredient — water.
Lemon water does contain some additional nutrients from the lemon juice, such as vitamin C and antioxidants, but these are unlikely to have any effect on your weight.
Additionally, the alkalizing effect of lemon juice has no clear effects on weight.
All that being said, lemon water may have some benefits for preeventing kidney stones, due to the acids it contains