Tom Collins: more than one standard drink in a tall sweet glass

In two small randomized laboratory studies, alcohol taken with a diet mixer produced a higher breath alcohol peak than the same dose with a sugar-sweetened mixer. In 12 adults given vodka and cola in an open-label crossover, the peak was 38.3 against 34.8 mcg/100 mL. In 16 social drinkers it was 0.091 against 0.077 g/210 L. Both used vodka with cola-type mixers, and we found no trial of the cocktail itself, so this applies to a Collins made with sweetener only by analogy. The regular version is a sizeable drink. As coded in the US survey database, one 225 g Tom Collins carries 18.7 g of alcohol, 36.2 g of sugars and about 277 calories, figures calculated from a recipe rather than measured in a glass. In the United States one standard drink is about 14 g of pure alcohol, so a single Collins made to that recipe is more than one.

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• One Tom Collins as coded in the US survey database (225 g) carries 18.7 g of alcohol, 36.2 g of sugars and about 277 calories. — Tom Collins, FNDDS food code 93301150, 1 drink = 225 g Evidence C source
  Per 100 g: alcohol 8.3 g, energy 123 calories, total sugars 16.11 g; per drink 18.7 g alcohol, 276.8 calories, 36.2 g sugars

What a real portion looks like

• In the United States one standard drink holds about 14 g of pure alcohol. — US adults, definition used in federal guidance Evidence E source
  1 standard drink = about 14 g (0.6 fl oz) pure alcohol
• Dutch adults pouring spirits at home served 3.2 tbsp (47 ml) on average, a third more than the 2.4 tbsp (35 ml) standard. — 201 adults in the Netherlands drinking wine or spirits at home weekly (n = 201) Evidence C source
  Straight spirits 3.2 vs 2.4 tbsp (47.0 vs 35 ml) standard; white wine 4.4 fl oz (129.4 ml) vs 3.4 fl oz (100 ml) standard

What your body absorbs

• In a randomized crossover trial of 12 adults, vodka mixed with diet cola gave a higher peak breath alcohol than the same dose with regular cola (38.3 vs 34.8 ug/100 mL). — 12 healthy adults aged 19-64 (8 men, 4 women), 0.5 g/kg alcohol, two sessions (n = 12) Evidence B source
  Peak BrAC 38.3 vs 34.8 ug/100 mL; gastric half-emptying 100 vs 111 min with diet vs regular mixer
• In a randomized placebo-controlled study of 16 social drinkers, vodka with a diet mixer produced a mean peak breath alcohol of 0.091 vs 0.077 g/210 L with a sugar-sweetened mixer. — 16 social drinkers, equal numbers of men and women, three sessions (n = 16) Evidence B source
  Mean peak BrAC 0.091 vs 0.077 g/210 L (diet vs regular mixer)

Safety, limits and interactions

• The CDC states that no amount of alcohol and no time in pregnancy is known to be safe for drinking. — Pregnant women and those who may become pregnant Evidence E source
  No known safe amount or safe time
• A systematic review of 16 population studies found that up to 88% of men and 79% of women using sedative-hypnotics also drank alcohol. — Middle-aged and older adults in 16 population-based studies (North America, Europe, Australia) (n = 16 studies) Evidence C source
  Up to 88% of male and 79% of female sedative-hypnotic users drank alcohol; up to 28% of drinkers used sedative-hypnotics

The bottom line

Home pours run large. In a Dutch study where 201 adults measured what they poured at home, straight spirits averaged 3.2 tbsp (47 ml) against a 2.4 tbsp (35 ml) standard, and cocktails were not measured. This page does not yet carry cards on the long-term health effects of alcohol, and their absence here is not evidence that drinking is harmless. The CDC states that there is no known safe amount of alcohol in pregnancy and no safe time during pregnancy to drink. A review of 16 population studies of middle-aged and older adults found that up to 88 percent of men and 79 percent of women who used sedative or sleeping medicines also drank alcohol. It counted how common the overlap is and did not measure harm. If you take such a medicine, the question of a cocktail belongs with the person who prescribed it.

Sources

1. tmcl-daily-r6-01 · food composition data
   Tom Collins 93301150: 1 drink 225 g; Alcohol, ethyl 8.3 G per 100 g (18.7 G per drink); Energy 123 KCAL per 100 g (276.8 KCAL per drink); Total Sugars 16.11 G per 100 g (36.2 G per drink)
   USDA FNDDS 2021-2023, food code 93301150 (FDC 2710653) · checked 2026-09-29
2. tmcl-daily-r6-04 · agency guidance
   In the United States, one standard drink contains about 14 grams, or about 0.6 fluid ounces, of pure alcohol.
   NIAAA (NIH), What Is A Standard Drink? · checked 2026-09-29
3. tmcl-daily-r6-06 · observational study
   also for straight spirits the poured amount was significantly more than the standard (47·0 v. 35 ml).
   Public Health Nutr, 2019 · checked 2026-09-29
4. tmcl-daily-r6-02 · randomized crossover trial
   Diet coke increased both the peak BrAC (38.3 ± 9.45 vs. 34.8 ± 6.82 μg/100 mL) and the area under the breath ethanol curve between 0 and 180 minutes (45249.0 ± 95.7 vs. 40439.25 ± 72.5 μg·min/L).
   Toxicol Lett, 2025 · checked 2026-09-29
5. tmcl-daily-r6-03 · randomized laboratory study
   Participants (n = 16) of equal gender attended 3 sessions where they received 1 of 3 doses ... The mean peak BrAC was 0.091 g/210 l in the alcohol + diet condition compared with 0.077 g/210 l
   Marczinski CA, Stamates AL. Alcohol Clin Exp Res, 2013 · checked 2026-09-29
6. tmcl-daily-r6-05 · agency guidance
   There is no known safe amount of alcohol use during pregnancy. There is no safe time during pregnancy to drink alcohol.
   CDC, About Alcohol Use During Pregnancy · checked 2026-09-29
7. tmcl-daily-r6-07 · systematic review
   Up to 88% of men and 79% of women who used sedative-hypnotics also consumed alcohol. Up to 28% of those who consumed alcohol were concomitant users of sedative-hypnotics.
   Ann Pharmacother, 2013 · checked 2026-09-29