Caffeine is the only effective performance-boosting ingredient in energy drinks, according to new research.
The Canadian study reviewed dozens of studies into ingredients such as taurine, guarana and ginseng and found there was an "overwhelming lack of evidence to substantiate claims that these ingredients boost performance".
There was some weak evidence for glucose and guarana extract, but the researchers concluded that caffeine was the only ingredient proven to have any mind and body-boosting powers.
Accredited practising dietitian Melanie McGrice told ninemsn that tea and coffee were much better choices for people wanting a caffeine hit.
"In addition to the caffeine, energy drinks are really high in sugar," she said.
"With such an obesity epidemic in Australia, for most people it's really not a good idea."
McGrice said a maximum of three coffees or five cups of tea is fine for adults.
"There's nothing wrong with adults drinking tea or coffee, as long as people are careful about the amount of sugar and syrups that are added," she said.
"But if you don't drink those, there is no reason to start drinking it. It's only for people who do drink tea or coffee already."
However McGrice said children should avoid caffeine in any form.
"Energy drinks are high in kilojoules and caffeine, neither of which we recommend to children," she said.
"Part of this is because the caffeine and the acid in them are bad for their growing bones. The Australian Dietary Guidelines for children actually recommend that children should only be drinking water or milk."
More than anything, McGrice said people need to be dealing with the cause of their fatigue, rather than looking for a band-aid solution in energy drinks.
"Part of the reason why people are needing energy in the first place is because they are not meeting their nutrition requirements –– having a healthy diet goes a long way in providing us with the energy we need," she said.
"Also getting enough sleep –– we really need seven to eight hours sleep a night."
Other studies have found energy drinks have up to 14 times more caffeine than ordinary soft drinks, and that too much caffeine can be linked with diabetes, heart problems, seizures and behavioural disorders.
The review was published in the Nutrition Reviews journal.
Related video: Cardiologist Chris Semsarian warns that energy drinks can trigger heart attacks and other serious cardiac conditions.