Caffeine: Amounts in Indian Drinks, Limits, Performance Evidence and Safety

Caffeine is a stimulant that occurs naturally in tea leaves, coffee beans and cocoa, and is added to energy drinks, pre-workout powders and tablets. It makes you feel more alert and, in trials, improves exercise performance by a small margin. ICMR-NIN's Dietary Guidelines for Indians (2024) advise that intake should not exceed 300 mg a day, which three or four cups can reach. FSSAI limits a caffeine supplement to 3 mg per kg of body weight a day, never more than 300 mg, and 200 mg in one dose. This entry belongs to the supplements section of the handbook.

Whether coffee itself helps or harms blood pressure, acidity and long-term health is a separate question, answered in is coffee good or bad for you, and the matching page for chai is is tea good for health. What follows is the reference material on the compound: amounts, limits, the sports evidence, label rules and cautions.

What is caffeine and what does it do?

Caffeine is a plant compound that acts on the brain. The International Society of Sports Nutrition (ISSN) describes it as the most widely consumed psychoactive substance in the world. Its shape resembles adenosine, a messenger that builds up through the day and dampens nerve activity. Caffeine occupies adenosine's receptors, so the brake is partly lifted, and most people notice better mood, focus and vigilance. The same action explains the unwanted effects: a racing pulse, restlessness and poor sleep.

The liver clears caffeine slowly. The ISSN position stand puts the average half-life at 4 to 6 hours, with a range in adults from 1.5 to 10 hours. Clearance slows in pregnancy and with hormonal contraceptives, and speeds up in smokers and heavy users. Two people can therefore drink the same cup at 5 pm and have very different amounts left in the blood at bedtime.

How much caffeine is in Indian tea, coffee and energy drinks?

ICMR-NIN gives the Indian reference figures per 150 ml cup: 80 to 120 mg in brewed coffee, 50 to 65 mg in instant coffee and 30 to 65 mg in tea. Energy drinks are defined by regulation instead of by measurement: FSSAI's standard for a caffeinated beverage requires at least 145 mg and at most 300 mg of caffeine per litre. A 250 ml can therefore holds roughly 36 to 75 mg, which is no more than a cup of brewed coffee. Ordinary carbonated drinks are capped at 145 parts per million.

The ranges are wide because the cup is not a fixed thing. A small steel tumbler of South Indian filter coffee diluted with milk is not a 150 ml cup of black brew, and roadside cutting chai is a smaller serving than a mug at home. Long boiling, more leaf and a bigger glass all push a cup of chai towards the top of its range. Count cups honestly, including the ones after dinner.

The Indian limits: ICMR-NIN's 300 mg and FSSAI's rules

ICMR-NIN sets no requirement for caffeine, because it is not a nutrient. What the 2024 guidelines give is a ceiling: moderation in tea and coffee so that caffeine does not exceed the tolerable limit of 300 mg a day. They add that the tannin in both drinks interferes with iron absorption, and advise avoiding tea and coffee for at least one hour before and after meals. That matters in a country where low iron is common; the iron entry explains why.

FSSAI regulates caffeine in two places. As a supplement ingredient, Schedule VI of the nutraceutical regulations permits 3 mg per kg of body weight a day, subject to a maximum of 300 mg a day and not more than 200 mg in a single dose, for adults only and not recommended for pregnant and lactating women. As a drink, the caffeinated beverage standard fixes the 145 to 300 mg per litre band and the label statements described further down.

What does the ISSN position stand report on exercise?

The ISSN's 2021 position stand concludes that caffeine has consistently improved exercise performance in trials at 3 to 6 mg per kg of body mass, most often taken 60 minutes before exercise. It adds that the smallest effective amount is unclear and may be as low as 2 mg per kg, and that very high amounts such as 9 mg per kg bring a high incidence of side effects without being needed for the benefit. Most of this research used plain caffeine in a capsule, because the amount in a cup of coffee is hard to standardise.

Aerobic endurance shows the most consistent benefit, described as moderate to large, while muscular endurance, strength, sprinting and jumping show small to moderate gains in many but not all studies. Caffeine is no longer a controlled substance in sport: the position stand records that it was removed from that category in 2004 and is still monitored. These are findings about trial protocols, not instructions, and a product sold in India cannot direct you beyond FSSAI's 200 mg single dose.

How strong is the evidence, and where is it weak?

For endurance exercise the evidence is strong in consistency and modest in size. The position stand cites a meta-analysis of 46 placebo-controlled studies in which caffeine at 3 to 6 mg per kg raised mean power output by 2.9 per cent and shortened time-trial completion by 2.3 per cent. For a recreational runner that is a small edge, well inside the difference made by sleep, training and the weather on the day.

The weak points are individual response and habit. A second pooled analysis quoted in the same paper found differences between caffeine and placebo ranging from a 3.0 per cent loss to a 15.9 per cent gain across 56 time trials, so some people gain nothing. One four-week study of 18 people who rarely took caffeine found that daily use removed the benefit; another found it shrank but persisted over 20 days. The paper received no funding, though several authors declare ties to supplement makers and one to a coffee company.

Does caffeine late in the day harm sleep?

Yes, in the one trial that tested timing directly, though it was small. Twelve healthy adults took 400 mg of caffeine at bedtime, three hours before or six hours before, each compared with a placebo night. All three timings disturbed sleep on a home sleep monitor. Taken six hours before bed, caffeine cut self-reported sleep by 41 minutes, a difference that fell short of statistical significance in the diary but was picked up by the monitor. A dose of 400 mg is about four cups of brewed coffee, so a single evening chai is a much smaller test.

A worked example: a runner in Chennai

This case is an illustration, not a real person. Take a healthy 31-year-old man in Chennai who weighs 68 kg, takes no medicines, and is training for a 10 km race. He drinks two cups of filter coffee and three cups of tea a day, and a friend has suggested a caffeine tablet before the race.

What must a caffeine label show under FSSAI rules?

An energy drink that meets the caffeinated beverage standard must print High Caffeine with the milligrams per serving, the declaration consume not more than 500 ml per day, and a prominent caution that it is not recommended for children, pregnant or lactating women, or persons sensitive to caffeine. A caffeine capsule or pre-workout sold as a nutraceutical must carry that word, the amount of each active ingredient, a recommended usage advisory, the warning NOT FOR MEDICINAL USE, known side effects and interactions, and a statement about storing it out of reach of children.

Common mistakes and myths about caffeine

The commonest mistake is counting only coffee. Tea, cola, energy drinks, chocolate and pre-workout powders draw on the same daily total, and the ISSN notes that servings range from 1 mg in milk chocolate to more than 300 mg in some supplements. The second is stacking: a pre-workout scoop on top of a normal day's chai. The third is taking tea with meals, against ICMR-NIN's one-hour advice on iron. The fourth is copying an athlete's amount without scaling it to your own body weight. Caffeine is often sold alongside creatine, which works in a different way and carries its own ceiling.

Side effects, safety and when to see a doctor

The side effects reported most often in the research are a fast heartbeat and palpitations, anxiety, headaches, insomnia and poorer sleep quality. A 2017 systematic review of 381 studies concluded that up to 400 mg a day in healthy adults is not associated with overt cardiovascular, behavioural, reproductive, acute or bone effects. That is a finding about healthy adults. The review itself called for more research on people with existing conditions, and India's own guideline figure is the lower 300 mg.

Pregnancy needs separate care. WHO's antenatal recommendations advise women taking more than 300 mg a day to lower their intake, to reduce the risk of pregnancy loss and low birth weight, and ICMR-NIN states that excess tea and coffee adversely affect fetal growth and should be minimised. FSSAI does not recommend caffeine supplements or energy drinks in pregnancy or lactation at all. The pregnancy diet guide covers the rest of the plate.

Ask a doctor before using caffeine tablets, pre-workouts or energy drinks if you have a heart rhythm problem, high blood pressure, an anxiety disorder, a sleep disorder or reflux, or if you take regular medicines of any kind. Children and adolescents should not be given them: FSSAI restricts the supplement to adults, and the energy drink label says not recommended for children. See a doctor promptly for chest pain, a sustained racing or irregular pulse, fainting or severe agitation after caffeine. Caffeine is not a treatment for tiredness that has a medical cause.

NNWA courses that cover caffeine and supplements

Caffeine is taught as a worked case in NNWA's Sports Nutrition and Dietary Supplements and Nutraceuticals courses. NNWA is a private skill academy based in Kolkata, and its teaching is online, in English and Hindi. These courses train people to coach healthy clients and to refer anyone with a medical condition to a doctor. Neither is a degree, and neither is a dietitian qualification.