Nutritionist Dr Sam Christie sorts some of the fiction from fact, to let you know what's myth and what might be worth trying.
Eating grapefruit will help burn fat
"No food has the ability to burn fat. This one is definitely for the myth pile! Grapefruit does, however, pack a powerful punch in terms of vitamin C. Just half a grapefruit a day provides more than 50% of the daily target for Vitamin C."
Dairy foods are fattening
"For the large majority of adults, there can only ever be a drawback with these foods when eaten excessively or exclusively. Dairy foods do seem to get such a bad press, even though they are an invaluable source of protein and micronutrients - some of which can actually help control weight.
"For example, Vitamin D - found in cheese and other foods like oily fish and eggs - is now thought to have insulin-sensitising effects, which ultimately means less fat stored in the body and more burnt-off as energy. With so many UK adults failing to reach their daily target for Vitamin D, dairy products need to be viewed as friends not foes, not forgetting that dairy foods pack the most bio-available punch when it comes to the essential mineral, calcium."
Eating food late at night is fattening
"There is little definitive evidence either way on this one. However, Eastern health philosophies strongly dictate that the digestive system is far from active in terms of digestive capacity at this time of day. Probably best to avoid regular practice of this one."
You shouldn't eat between meals
"A real golden oldie! It's the nature of what you eat during the day that is critical for achieving and maintaining a healthy weight, not the number of times you eat a day. Researchers have shown that the desire to snack between meals on sweet foods can be significantly reduced when levels of the mineral chromium are sufficient in our bodies. Using a supplement of chromium for 12 weeks or so can lead to fewer chocolate cravings - try Chromium GTF 200mcg, £9.95, from Nature's Best."
Drinking too much water will give you water retention
"Highly unlikely! However, making sure that you eat your way through 5-a-day fruit and veg will help support the health and strength of the small blood vessel network in your body. These delicate capillaries, if leaky or over-porous, can cause diffuse forms of fluid retention (often worse before a period).
"Fluid ends up waterlogging tissues, instead of being efficiently whisked away. It is known that specific phytochemicals, natural, plant-derived compounds known as anthocyanidins, from certain vegetables, fruits and berries can help repair and strengthen the leaky, damaged bits of blood vessels and actually treat the cause of puffy legs, tummies and fingers. Try Colladeen, £14.95, the only scientifically-trialled anthocyanidin extract for diffuse fluid retention in UK women."