What could be healthier?
A week chock full of kilos of fruits and veggies, juiced so that goodness is easily digested and spread throughout your body.
It might sound good, but like any diet plan where food groups are restricted, juice cleanses might not be giving you any real health benefits.
The cleanses usually consist of three or five days where you drink nothing but fruit and veg juices, sometimes with a vegetable soup, which is supposed to flush out all the nasty stuff built up in your body and give your digestive system a break.
But accredited practising dietitian Eleanor Beck says there is no need to "rest" your digestive organs or detox your body, because it already does so quite efficiently.
"We've got organs in our body, like the liver and kidneys, that already clear our body of waste," she says.
"I'd argue that all we need to do actually make those organs function really well is be careful of the amount of alcohol we drink and saturated fat we eat, and if we watch those things in our day-to-day diet, then there's absolutely no need to do anything more to make sure your body is functioning quite well."
The new year is often a time for people to look for ways to improve their health and wellbeing, and cleansing programs such as these can seem like a good way to get things started.
Most of these cleanses meet recommended kilojoule requirements because they are not designed as weight loss programs, but rather as a way to boost your energy levels and stop you feeling lethargic.
However, while eating lots of fresh greens is good for you, it is better to eat them whole, as juicing can reduce fibre content - a crucial part of any diet.
"Regular amounts of high fibre in the diet are more likely to maintain what they call the gut microbe biota, so I would argue you should have plenty of fibre all the time.
"The body and your digestive system are designed to be used and so we should use it."
There is no concrete scientific evidence that cleanses and detoxes have any real benefit and Beck says advising someone to drink only fruit and vegetable juices is not advice that would be taught to upcoming dietitians at university.
"While these cleanses won't be harmful, there's no reason those ingredients can't be eaten as whole food," says Ms Beck.