Losing weight can be a challenging process. Many people look for ways to boost their weight loss efforts through diet, exercise or other lifestyle changes. Some claim that drinking grapefruit juice can help promote weight loss. This article explores whether grapefruit juice actually helps with weight loss.
How Grapefruit Juice May Promote Weight Loss
There are a few ways that grapefruit juice may help with weight loss:
Some studies suggest that grapefruit juice may increase feelings of fullness and decrease appetite. This can lead to eating fewer overall calories, which is key for weight loss.
One study in 91 obese participants found that drinking grapefruit juice before meals increased feelings of satiety and led to eating fewer calories at meals (1).
Increasing protein intake and limiting carbohydrates are two other science-backed ways to increase satiety and support weight loss efforts (2, 3).
Drinking grapefruit juice may also give metabolism a modest boost. Your metabolism determines how many calories you burn at rest and is an important factor in weight control.
An older study in 85 participants showed that drinking grapefruit juice increased metabolism by over 30% for over 3 hours after consumption (4).
Boosting physical activity, building muscle mass and eating spicy foods are other ways you can give your metabolism a lift to aid weight loss (5, 6).
Regulating Blood Sugar
Keeping blood sugar levels stable is key to appetite regulation and weight control (7).
Grapefruit juice contains compounds that may help regulate blood sugar. Naringin and naringenin are two antioxidant compounds in grapefruit juice that animal and human studies suggest may increase insulin sensitivity and stabilize blood sugar levels after meals (8).
Pairing grapefruit juice with a balanced diet and regular exercise are other effective ways to maintain healthy blood sugar levels (9).
Inhibiting Fat Formation
Some research indicates that grapefruit juice may prevent fat formation and increase fat breakdown. However, the evidence on this potential effect is mixed.
One study found that naringenin, a compound in grapefruit juice, blocked fat formation in cells by up to 80% in test tube and animal studies (10).
However, several other studies did not find any beneficial effects on fat burning (11, 12). More research is needed to understand grapefruit juice’s effects on fat metabolism.
Downsides of Grapefruit Juice for Weight Loss
Despite the potential benefits above, there are some downsides to consider when it comes to drinking grapefruit juice for weight loss:
High in Calories and Sugar
Grapefruit juice can be high in calories and sugar, especially store-bought varieties. Drinking too much may undermine weight loss efforts.
An 8-ounce (240-ml) serving can contain over 100 calories and 20 grams of sugar (13). For comparison, the same serving of orange juice has 112 calories and 21 grams of sugar (14).
Overconsuming liquid calories and added sugar is linked to weight gain and obesity (15). Enjoy grapefruit juice in moderation or select low-sugar varieties to maximize potential benefits while limiting calorie intake.
May Interact With Certain Medications
Grapefruit contains compounds that inhibit cytochrome P450, an enzyme your body uses to metabolize certain medications.
If you take certain medications, drinking grapefruit juice could cause them to build up in your bloodstream to potentially dangerous levels (16).
Check with your healthcare provider for potential grapefruit interactions with any medications you take.
Acidic and Hard on Tooth Enamel
Like other citrus juices, grapefruit juice is highly acidic. Drinking a lot of acidic beverages over time can degrade tooth enamel and increase your risk of cavities (17).
Rinsing your mouth with plain water after drinking citrus juices can help protect your teeth. Waiting at least 30 minutes after consuming acidic foods and beverages before brushing teeth is also recommended to prevent damage to tooth enamel (18).
Does Grapefruit Juice Promote Weight Loss?
Some studies suggest grapefruit juice may boost weight loss, while others show no effect. Here is a summary of key findings:
|91 obese participants
|Randomized controlled trial
|Drinking 1/2 grapefruit before meals for 12 weeks resulted in more weight loss than drinking water.
|85 healthy participants
|Randomized crossover trial
|Drinking grapefruit juice increased resting metabolic rate compared to drinking water.
|57 overweight women
|Randomized controlled trial
|Drinking 1/2 grapefruit before meals did not affect weight loss over 12 weeks compared to drinking water.
|39 obese participants
|Randomized controlled trial
|Drinking 1/2 grapefruit 3 times per day for 6 weeks did not improve weight loss compared to drinking water.
As you can see, the research is mixed. Some studies show that grapefruit juice may increase weight loss, while others show no significant difference compared to drinking water.
More large, high-quality studies are needed to determine grapefruit juice’s true effects on weight.
Other Tips to Maximize Weight Loss
While the effects of grapefruit juice are inconclusive, here are some tips supported by stronger scientific evidence that may promote weight loss:
Increase Protein Intake
Eating more protein increases feelings of fullness, decreases levels of the hunger hormone ghrelin and increases the number of calories burned (19, 20).
Aim to eat 0.7–1 grams of protein per pound (1.6–2.2 grams per kg) of body weight daily as part of a balanced diet (21).
Reduce Added Sugars
Added sugar provides excess calories with little nutrition. Limiting foods and beverages high in added sugars is an effective way to reduce calorie intake (22).
The American Heart Association recommends limiting added sugars to no more than 100 calories per day for women and 150 calories per day for men (23).
Fill up on Fiber
Soluble fiber absorbs water to form a gel, slowing digestion and nutrient absorption. This leads to decreased appetite and calorie intake (24).
Good sources include beans, oats, flaxseeds, vegetables, fruits and psyllium husk.
Drinking water, especially before meals, can aid weight loss. One study in 48 adults found that drinking 500 ml (17 oz) of water 30 minutes before meals reduced calorie intake and caused greater weight loss (25).
Aim to drink at least 6–8 cups (1.4–2 liters) of water per day.
Engaging in aerobic and resistance training can help boost metabolism and increase fat burning while preserving muscle mass (26, 27).
Aim for at least 150 minutes of moderate activity or 75 minutes of vigorous activity per week, along with at least two weekly strength training sessions.
The Bottom Line
While grapefruit juice provides some potential benefits related to weight loss, its effects are mixed overall. More research is needed on grapefruit juice specifically.
That said, consuming it in moderation may aid weight loss when paired with a healthy diet and active lifestyle. Just be mindful of limiting added sugars and calories from juice in general.
Focusing on proven strategies like eating more protein, reducing added sugars, staying hydrated and exercising regularly can all support your weight loss journey.