Nutritionists are warning that many smoothie and juice diets are not as "healthy" as they seem to be, as some can actually make you gain more weight.
Experts at Tesco have highlighted options that are considered healthy but may cause weight gain.
It includes olive oil, juice, chicken, granola, dried fruit and nut mixes, and low-fat biscuits.
Catherine Matthews, a nutritionist, said "You may think a fruit or veggie smoothie is packed with vitamins and minerals, but it's also laden with sugar. Some contain as much sugar as fizzy drinks."
An example is Tesco's Finest Mango Fair Trade Smoothie, which seems to be healthy, as it contains a myriad of fruit. But it actually has more sugar in it than Coke.
And olive oil has long been lauded as a healthy option for salad dressing and breads, but Matthews said it is a whopping 50 calories per teaspoon.
Though many believe honey is healthful and low-fat, Matthews said it was just sugar, and can still cause weight gain when eaten regularly.
She said the fastest way to gain weight is to drink fruit juice.
The reason for this is because it is easy to consume fruit juice calories, taking less than a minute to drink a 300ml glass of juice with 150 calories. That's more than the 139 calories in a 330ml can of Coke.
Matthews also criticized low-fat yogurt, biscuits and other treats as they have more calories than their standard versions because manufacturers pack them with sugar to make up for the loss of flavor.
Perhaps most surprising was her warning about chicken, as the meat has always been classified as better and healthier than red meat.
She said chicken has the tendency to be high in calories, depending upon how it is cooked. Leaving the skin on it and putting it in a frier, for instance, raises the calorie count from 100 to 300.
The perfect diet, according to Matthews, is a high-protein breakfast, like eggs, and plenty of fruit and vegetables throughout the day.
Sources: Daily Mail