Fasting has become an increasingly popular way to lose weight quickly. Proponents claim that fasting helps speed weight loss by lowering calorie intake, reducing appetite, increasing fat burning, and improving metabolic health. Many people add lemon water to their fasting regimen, believing it provides additional weight loss benefits. But does drinking lemon water actually help boost weight loss during a fast? Here is a detailed look at the evidence.
What is intermittent fasting?
Intermittent fasting (IF) is an eating pattern that involves regular fasting periods. Rather than restricting what you eat, it controls when you eat. There are several popular IF protocols, including:
16/8 method
This involves fasting for 16 hours per day and restricting food intake to an 8-hour window. For example, skipping breakfast and only eating between 12–8 pm. It’s the most popular IF protocol.
5:2 diet
This type of fasting involves severe calorie restriction (about 500–600 calories) for 2 nonconsecutive days per week but eating normally the other 5 days.
Alternate day fasting
Fasting every other day. On fast days, some alternate day fasting plans allow about 500 calories.
The Warrior Diet
This involves eating small amounts of raw fruits and vegetables during the day and one huge meal at night.
Eat Stop Eat
Fasting for 24 hours 1–2 times per week. For instance, fasting from dinner to dinner or breakfast to breakfast.
The most common IF protocols are the 16/8 method and 5:2 diet. Many people find IF an easier approach to weight loss than traditional calorie restriction.
Does intermittent fasting promote weight loss?
Many studies show that IF can be an effective strategy for weight loss:
A 2018 review
This looked at 40 studies on various IF protocols. Intermittent fasting was found to cause 3–8% weight loss over 3–24 weeks, with greater weight loss seen in studies with longer durations (1).
A 2017 review
This examined over 25 IF studies with 1,075 participants. Intermittent fasting was found to promote comparable weight loss to traditional calorie restriction. Participants lost 4–7% body weight over 10–52 weeks (2).
A major 2016 review
This analyzed 50 human studies on various IF protocols. Intermittent fasting was found to cause 1.2–6.6% greater weight loss than non-fasting protocols. Alternate day fasting caused the most weight loss (3).
Overall, most research indicates that IF can be an effective approach for weight loss, comparable to traditional calorie restriction. It seems particularly effective for short-term weight loss of up to 12 weeks (4).
How does intermittent fasting promote weight loss?
Here are 5 key ways intermittent fasting may spur weight loss:
1. Lower overall calorie intake
By restricting eating to certain time periods, you naturally reduce the number of hours you can consume calories. This creates a calorie deficit needed for weight loss (5).
2. Appetite reduction
Fasting may suppress levels of the hunger hormone ghrelin. This leads to decreased appetite, allowing easier calorie restriction (6, 7).
3. Increased fat burning
Fasting triggers metabolic adaptations that enhance fat breakdown and utilization for energy (8, 9).
4. Improved insulin sensitivity
Intermittent fasting can improve insulin sensitivity, which may optimize fat burning and stabilize blood sugar (10).
5. Healthier food choices
People naturally tend to make healthier food choices during scheduled eating periods (11).
So intermittent fasting can boost weight loss on several levels—from increasing fat burn to reducing calorie intake and appetite.
What is lemon water?
Lemon water is simply water infused with fresh lemon juice. It provides vitamin C, antioxidants, and small amounts of nutrients like potassium, magnesium, and vitamin B6 (12).
Potential benefits of lemon water include:
- Boosting immune function
- Aiding digestion
- Promoting hydration
- Preventing kidney stones
- Supporting weight loss (according to some)
Lemon water is often consumed in place of higher calorie beverages. It has become popular to drink as a morning ritual.
Does lemon water help with intermittent fasting?
Proponents claim that adding lemon water to your intermittent fasting plan provides the following benefits:
Promotes fat burning
Some claim that lemon water’s pectin fiber and citric acid help reduce appetite and increase fat burning during the fasted state. However, no studies support this benefit.
Aids detoxification
Lemon water is said to stimulate liver detoxification and kidney function. However, your kidneys and liver don’t need help detoxifying if you are healthy.
Boosts metabolism
Some assert that lemon water kick starts your metabolism first thing in the morning. But no evidence proves lemon water has any special ability to speed up your metabolic rate.
Reduces appetite
Drinking warm lemon water on an empty stomach is said to control hunger signals and cravings. The mechanism involves stomach distension and altered ghrelin levels. But no solid research exists.
Promotes bowel regularity
The high vitamin C and citric acid content of lemon juice may help flush out your digestive system. This could reduce abdominal bloating.
Improves mood
Lemon scent is claimed to reduce anxiety, depression, and improve mood and focus. But more research is needed on aromatherapy and mood.
Overall, there’s not much scientific evidence that lemon water provides significant benefits for intermittent fasting weight loss regimens. More research is needed.
Should you drink lemon water while fasting?
Here are some things to consider regarding lemon water during intermittent fasting:
It won’t break your fast
Lemon water is very low in calories and carbs, so it shouldn’t interfere with fat burning during the fasted state.
It may reduce hunger and cravings
Having a warm, flavored drink in the morning could lessen appetite and prevent breaking your fast too early.
It boosts hydration
Starting your day with lemon water encourages proper hydration. Proper hydration enhances liver and kidney function.
The flavor can be appealing
The tart, sour lemon flavor can help make your fasting period more enjoyable. This may improve compliance with your regimen.
It provides vitamin C
Lemon water first thing on an empty stomach maximizes your vitamin C intake from the citrus.
It avoids problematic foods
Replacing sugary fruit juices and caloric coffees and teas with lemon water prevents intake of foods that could break your fast.
So while lemon water may offer some benefits, they seem to be based more on replacing problematic beverages and reducing appetite signals rather than any special properties of the lemon water itself.
Nutrition facts for lemon water
Here is the nutrition information for 8 oz (240 ml) of lemon water made with juice from 1 lemon wedge:
| Calories | 6 |
|---|---|
| Total fat | 0 g |
| Sodium | 0.5 mg |
| Potassium | 26 mg |
| Total carbs | 2.5 g |
| Sugars | 0.5 g |
| Protein | 0.1 g |
| Vitamin C | 9 mg (15% DV) |
As you can see, lemon water is very low in calories, carbs, and protein. It provides vitamin C but in small amounts.
Is lemon juice okay during a water fast?
For plain water fasting, most people avoid adding lemon juice or other flavorings to the water. Since truly fasting involves only water, lemon juice could be considered cheating.
The small amounts of calories and carbs in lemon juice can activate digestive processes. This could increase hunger levels during a water fast.
If you decide to add some lemon, limit it to a thin slice or small squirt of juice. Too much lemon flavor may make fasting more difficult by stimulating appetite.
Tips for adding lemon to your intermittent fasting plan
Here are some tips for incorporating lemon water into your IF regimen:
– Drink it cold or warm. Both have benefits. Warm lemon water is soothing for the stomach. Cool lemon water is refreshing.
– Add lemon slices or lemon juice. Slices add nice flavor but may be abrasive for teeth with repeated use. Juice avoids this problem.
– Start your day with it. Drinking lemon water first thing may reduce morning hunger and cravings.
– Use purified water. Tap water contains chlorine and fluoride that may diminish lemon benefits. Filtered water is ideal.
– Don’t overdo the lemon juice. Too much can upset your stomach, erode teeth enamel, and trigger reflux issues.
– Sweeten cautiously. If needed, use small amounts of honey, maple syrup, or stevia instead of sugar.
– Combine with ginger or mint. Adding sprigs of mint or slices of ginger can enhance lemon water’s flavor and benefits.
– Avoid at night. The acidity can wear down tooth enamel. Brushing teeth prior helps mitigate this effect.
Risks and precautions with lemon water
Lemon water is likely safe for most people when consumed in moderation. However, some risks and precautions include:
– Dental erosion. Too much lemon juice could wear away tooth enamel over time. Use a straw to minimize exposure to teeth.
– Heartburn. The acidity may trigger reflux and heartburn in those susceptible. Monitor your response.
– Drug interactions. The citric acid may interact with certain medications like diuretics or lithium. Consult your physician.
– Blood sugar spikes. The carbs in lemon juice could affect blood sugar control for diabetics or prediabetics. Monitor levels.
– Sensitivity. Some people may experience migraines, rashes, or headaches from lemon compounds called salicylates.
Overall, lemon water is quite safe when consumed in moderate amounts. Those with digestive issues may need to minimize intake.
The bottom line
Here is a summary of the key points:
– Intermittent fasting can be effective for weight loss, with or without lemon water.
– Lemon water is unlikely to boost the weight loss effects of intermittent fasting.
– Any benefits are more theoretical and come from avoiding problematic beverages.
– Lemon water may help reduce hunger and cravings during the fasted state.
– Drinking it black or with a small amount of lemon is fine, but don’t overdo the lemon juice.
– Lemon water provides vitamin C, hydration, and flavor variety but has minimal calories.
– For plain water fasting, adding lemon juice may stimulate hunger or tiny insulin releases.
– Use purified water and monitor for any digestive issues, reflux, or tooth enamel erosion.
So feel free to add lemon to enhance the flavor and enjoyment of your intermittent fasting regimen. Just don’t expect dramatic results from any magical properties of the lemon water itself. As with any supplement, let your results and tolerance be your guide.
The takeaway
Intermittent fasting is an effective, research-backed approach for weight loss. Lemon water is unlikely to boost intermittent fasting weight loss effects but can help keep you hydrated and satisfied. For most people, enjoying lemon water during the fasting window appears to be safe and beneficial for reducing appetite. Let your personal results and tolerance guide you.