This leaflet explains what you need to know about alcohol as someone with diabetes. It covers what sensible drinking limits are, what precautions you should take and how best to prevent having a hypo whilst drinking.




Recommended Amounts 

Having diabetes does not mean that you need to avoid drinking alcohol. In fact, government guidelines for sensible drinking are the same if you have diabetes or not.

  • Men and women are advised not to regularly drink more than 14 units / week
  • Pregnant women are advised that no level of alcohol intake is safe in pregnancy
  • If you drink as much as 14 units a week, it is advisable to spread this over three or more days. If you have one or two heavy drinking sessions each week there are increased risks to health 

The risk of developing a range of illnesses, including increased blood pressure and certain cancers increase if you consistently drink more alcohol than the recommended amounts.

Alcohol Unit Guidelines 

As alcoholic drinks come in different strengths and sizes, units are a good way to tell how strong your drink is.

1 unit of alcohol is 10mls or 8grams of pure alcohol.  Drinks that contain 1 unit include:

  • One single pub measure (25mls) of spirits (40 % ABV
  • One half pint of normal strength lager, beer or cider (3.5% ABV)
  • One small glass (100mls) of wine (10% ABV)
  • One glass (50mls) of liqueur, sherry or other fortified wine (ABV = 20%) 

Look at the table 1 for the alcohol content of some common drinks.

Over time, the alcohol content of drinks has continued to increase, with many wines and beers being stronger than the more traditional ordinary strengths. So a drink may be stronger than you think. Remember too that many measures, particularly home measures are larger than standard sizes.

A more accurate way of calculating units is by the percentage alcohol by volume (ABV). This is the percentage of alcohol in one litre of the drink.

For example:

  • A wine of 14 % ABV has 14 units in a litre.
  • If you drink 125 mls you have had 1.75 units
  • If you drink 250 mls you have had 3.5 units

The Effect of Alcohol on Blood Glucose 

Increases Blood Glucose 

Alcohol can affect blood glucose levels in different ways. When having a drink that contains carbohydrate, with examples including real ale, liqueurs, dessert wines, it is likely that you may initially notice an increase in your blood glucose levels. If having a drink that does not contain carbohydrate, with examples including gin and slim line tonic, vodka and diet coke, red wine, you may not initially notice any immediate change in your blood glucose level. 

Decreases Blood Glucose 

When alcohol is processed in the liver, it can contribute to a drop-in blood glucose levels. This is because alcohol interferes with the normal release of stored glucose from the liver and so blood levels can fall, even if extra carbohydrate is eaten. This is important to be aware of if your diabetes is managed by insulin or sulphonylurea drugs e.g. Gliclazide, as this could result in the development of low blood glucose (hypoglycaemia). This will not occur if you are treated with diet and other medications.

If you are concerned about the impact of alcohol on your blood glucose, speak with your diabetes team who will be able to give you advice based around your personal circumstances. 

Ways to Prevent Alcohol Related Hypoglycaemia 

There are a few general rules to help prevent hypos when drinking alcohol:

  • Avoid drinking on an empty stomach
  • Take regular carbohydrate based snacks during and before bed
  • Monitor blood glucose levels closely
  • Always carry hypo treatment and have next to your bed
  • Make sure that the people you are with know that you have diabetes and how alcohol affects your blood glucose
  • Stick to recommend daily units of alcohol
  • Alternate alcohol drinks with sparkling water, sugar free lime and soda or diet drinks 

Watching Your Weight 

Alcohol contains 7 calories per gram, which usually offer no nutritional value. If you are concerned about your weight, consider the following:

  • Home measures tend to be more generous
  • Check all mixers and soft drinks are sugar free or diet varieties
  • Use ordinary strength beers, lagers and ciders. Low alcohol varieties can be higher in sugar, with low sugar versions being higher in alcohol
  • Avoid large quantities of drinks with a high sugar content e.g. sweet sherry, dessert wines, liqueurs and alcopops


Look at table 1 for the calorie content of some common drinks: 

Table 1: Alcohol and Calorie Content of Common Drinks


Alcohol Units

Calories (kcal)

25 mls spirit (ABV 40 %)

1 Unit


50 mls liqueur (ABV 17%)

1 Unit


275 alcopop (ABV 5.5%)

1.5 Units


330 mls lager (ABV 5%)

1.6 Units


175 mls wine (ABV 13%)

2.3 Units


Bottle wine (ABV 13%)

10 Units


125 mls champagne (ABV 12%)

1 Unit



Regularly drinking more than is recommended can increase the risk of serious health problems including certain cancers; liver disease; stroke; high blood pressure and mental health.

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