Alcohol · ~55 kcal per single measure (25 ml, 40% ABV)
Does spirits break a fast?
Yes. A 25 ml measure of vodka, gin or whisky has about 55 kcal from alcohol, so spirits break a fast. No level of alcohol is safe for health.
The answer for each goal
Weight loss
Breaks fastAutophagy
Breaks fastGut rest
Breaks fastBlood sugar
Grey areaSpirits such as vodka, gin and whisky are usually 40% alcohol by volume (ABV). A 25 ml single measure has about 55 kcal. A US shot of 44 ml (1.5 fl oz) has about 97 kcal, and 100 ml has about 220 kcal. All of those calories come from the alcohol, at about 7 kcal per gram.
Weight loss is the first of the site's own four fasting goals. A single measure is above the 50-calorie line, a common rule of thumb, not an official limit, so it breaks a weight-loss fast. Alcohol also cuts fat burning for a few hours. In a small study of 8 men, a drink with 24 g of alcohol cut fat burning by 73%. That is early evidence from one study.
Spirits break a fast for autophagy and gut rest as well, since the alcohol brings calories and is absorbed through the gut. Neat spirits have no sugar or starch, so blood sugar is the one grey verdict. This site never marks alcohol safe for any goal.
Mixers change the blood-sugar answer. Tonic, cola and fruit juice add sugar, and a sweet mixer breaks a blood-sugar fast. Soda water or a diet mixer adds almost nothing, but the spirit itself still ends the fast.
Food slows how fast alcohol is absorbed, so a drink on an empty stomach reaches the blood faster. Keep any drinking to your eating window, with a meal. No level of alcohol consumption is safe for health. If you take insulin or other diabetes medicines, talk to your doctor before you combine alcohol and fasting.
Watch out
A double measure (50 ml) of 40% spirit is about 100 to 110 kcal before any mixer. On a fasted, empty stomach the alcohol reaches your blood faster.
Questions people ask
Can you drink alcohol while intermittent fasting?
Not during the fasting window. Every alcoholic drink has calories, and a 25 ml measure of spirit is about 55 kcal. If you drink, keep it to your eating window and have it with food.
What is the best alcohol for intermittent fasting?
No alcohol keeps you fasted, and no amount is safe for health. By calories, a 25 ml measure of spirit with soda water is about 55 kcal. A 175 ml glass of 12% wine is up to about 160 kcal, and a pint of beer 180 to 250 kcal.
Does vodka break a fast?
Yes. A 25 ml measure of 40% vodka has about 55 kcal, and a US shot about 97 kcal. That breaks a fast for weight loss, autophagy and gut rest.
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