You have probably noticed that protein bars have taken over many a shop shelf over the last twelve months or so, and have become a go-to snack for everyone from top athletes to the occasional weight-lifter.

Philip Boucher-Hayes chats to top nutritionist Dr Sharon Madigan in the first episode of his new series What Are You Eating? tonight on RTE1 to find out if we really need these protein bars.

The appeal is that when you're involved with heavy exercise you're generally told to increase your protein intake, however Dr Madigan points out that you would be just as well eating eggs, and for a fraction of the cost.

Dr Madigan, performance nutritionist for the Irish Olympic boxing team, says: "You can buy twelve eggs probably for less than one of these bars. Three eggs will give you 18 grams of protein. For most of us 18-20 grams of protein is enough. For some of the athletes that require 4- and 5,000 calories a day, they are particularly useful... I think we are even talking about a certain subset of athletes as well."

She added: "It is definitely filling the void. At the end of the day, they are a bar. When you go out to buy one of these, what I would suggest to you is you really look at what you are buying. You need to really check your labels. Where the message maybe is that it’s reduced sugar or lower in sugar, polyols take that place – xylitol, sorbitol, mannitol, which are the common ones that you would see. They are generally lower in calories than your usual sugars. They are also very, very sweet in taste so, actually, you don’t need to use as much of them, so, that is where their benefit lies."

Watch the interview below, while you can the full episode of What Are You Eating? tonight on RTE1 at 8.30pm.