Coffee might be the drink of choice for office workers and cyclists, but more than one a day will make it difficult for you to go to sleep that night, according to nutritionist Kate Freeman.

Caffeine makes the body work more efficiently by increasing the blood-flow to the muscles but is not dose-dependant, meaning a double shot is no better than a single shot, she says.

''It's like taking five vitamin C tablets in one go when the extra tablets don't make any difference,'' Ms Freeman says.

She says chain coffee drinkers are not getting any of the benefits of consuming the stimulant in large amounts, but all of the drawbacks.

Numerous cups of coffee a day can give people heart palpitation, the jitters and make them feel on edge.

People not sleeping well often find out the cause is too much coffee, because caffeine stays in the body for eight to 10 hours.

Those cutting back on food to lose weight often mistakenly drink more coffee to give themselves a pick-me-up during the day.

''Three flat whites could be 600 calories,'' Ms Freeman says.

Some cyclists may even be getting a caffeine hit during their ride - without even knowing it.

Cyclist and former barista Robert Bleeker says the high-sugar gels consumed by riders to boost their energy often contain lots of caffeine.

The 51-year-old says the social pull of coffee would remain strong among his kind because all sorts of cyclists met at cafes - from hipster cyclists to road racers and mountain bikers.

''I can't drink too much coffee - it hurts my stomach,'' he said.