It’s January! Time to do all those things you vowed you’d start as soon as the new year came round.
Like, maybe, dieting.
But before you start on any of the following diets, you should know about the science (or lack of) behind them.
1. Paleo diet.
This lifestyle is based on what people ate in the Paleolithic period, between 2.5 million and 10,000 years ago, with the premise that our biology hasn’t changed since then. People on a Paleo diet eat lots of meat and some vegetables, but no beans or other legumes, and no dairy.
The trouble is the science this diet is based on is not all there. Our biology has changed since the Paleolithic era. One example is lactose. Our ancestors’ bodies used to turn off the gene used to break down lactose after infancy. But once we started eating dairy on a regular basis, we developed a mutation that kept it turned on. Other things have changed, too. Our gut bacteria is almost certainly different now and the foods we eat have also changed beyond recognition since then.
If this diet appeals to you, here’s one thing you should take from it: cut down on processed food.
2. Raspberry ketone supplements.
Raspberry ketone is the main compound that gives raspberries their aroma. It’s also used as a food additive, and was approved for food use by the US Food and Drug Administration in 1965.
But there’s no evidence that it’s safe as a supplement. Crucially there’s also no evidence that it actually helps you lose weight. In tests on rats it appeared to protect them from obesity, but no such trials have been reported in humans.
Monomeals are exactly what they sound like: a meal of just one fruit or vegetable, like a pile or oranges or a bowlful of strawberries.
Some people think that your gut gets tired when trying to digest more than one type of food. But there’s no truth to that. In fact, combining foods can help you absorb some nutrients.
Ok, you can devour a bunch of bananas for dinner once in a while if you want to, and eating plenty of fruit and veg is a good idea, but it’s also important to get a balanced diet.
4. The blood type diet.
This diet is based on the notion that different blood types – A, B, AB and O – need different diets, because each blood type evolved during a different period of Earth’s history. If that sounds ridiculous, it’s because it is.
There is some evidence for differences in the likelihood of developing certain diseases depending on your blood type. For example, people with type A, B and AB seem to be more likely to develop pancreatic cancer than people type O blood. And type O people are more susceptible to cholera and the plague.
But there’s no need to tailor your diet to your blood to prevent diseases – just eat as healthily as you can.
5. The 5:2 diet.
This diet was popularised by a BBC Horizon documentary in 2012. It consists of eating normally for five days a week, and fasting on the other two.
There is some evidence that this diet does lead to weight loss (at least among the overweight women involved in this study). But the NHS says that more evidence is needed to uncover any side effects and long term problems that might arise. (They recommend consulting your doctor before trying this diet out, too.)