We see how five popular diets measure up
Many of us have started diets only to throw in the towel after a few weeks, so how do you find a diet that works? Our nutrition experts weigh up six of the most common diets, including the Atkins diet and the low GI diet to see if they work.
1. Raw Food Diet
The Raw Food Diet is based on all, or a high proportion of the food you eat, being raw, plant-based food. Animal flesh of any kind should be avoided along with refined foods such as dairy, cereal grains, salt and sugar.
The theory
Advocates say that raw food contains all the nutrients and enzymes that are otherwise lost in the cooking process. The plan is based on the idea that if your diet is nutrient-rich, then you don’t need as many calories, therefore you lose weight. Supporters believe that raw food is in keeping with our genetic makeup whereas cooked food isn’t.
Does it work?
“The raw food diet is effective for those who are quite robust and hardy, and have a strong digestive system. For those who are generally weaker, quite thin, feel the cold easily and don’t have a strong digestive system, this diet can mean that they aren’t getting enough warming foods or calories to stay healthy. It really all depends on the metabolism and constitution of the individual,” says Ed Berger, naturopath and herbalist.
2. GI Diet
The Glycaemic-Index diet, or GI diet ranks carbohydrate foods in terms of how they affect blood-glucose levels. Foods with a low GI are absorbed more slowly and keep blood sugar levels constant. Those with a high GI have the opposite effect. Foods like wholegrains, veg and pulses for example, have a low GI whereas refined, sugary foods have a high GI.
The theory
By avoiding all sugary foods and those with a high GI, the idea is that you will lose weight due to less insulin being released. It’s been shown that reduced insulin levels can help the body burn fat.
Does it work?
“The GI diet has scientific credibility, but the foods are awarded their numbers on an individual basis, yet we eat them together. To add up the glycaemic load, it means looking at the percentage of foods on your plate for every meal, which can be hard to maintain. When done properly, these diets can help with weight loss,” says dietician Sarah Schenker.
3. Food combining
This diet works on the principle that the body digests carbs and proteins in different ways, so they shouldn’t be eaten in the same meal. Ideally, you should also eat four times more foods that raise alkali levels in the blood, (including veg, salads, fruit and milk for example), than foods that raise acid levels (such as animal protein, nuts, citrus fruits and carbohydrates).
The theory
Eating in this way maximises the body’s digestive powers while minimising its fat-storing habits. The theory is protein and carbs ‘fight’ each other and produce toxins in the body that may be stored as fat.
Does it work?
“Scientifically, there isn’t evidence to support this diet. It is often a successful method of weight loss, as many people tend to limit or leave out carbohydrates altogether and eat their protein along with fruit, salad or veg. In this respect, it becomes a low-carb diet,” says Linda Lazarides, author of The Waterfall Diet.
4. Atkins Diet
The Atkins diet involves restricting or even cutting out your carbohydrate intake, but consuming plenty of protein. High-sugar foods, breads, grains, pasta, cereals and starchy vegetables should therefore be limited or eliminated, while foods like meat, fish, eggs, cheese and butter can be eaten in abundance.
The theory
Dr Atkins believed that too much carbohydrate in the diet causes the body to produce too much insulin, and this in turn leads to hunger and weight gain. The Atkins diet says that, by eating foods that are high in fat and protein and reducing high-carbohydrate foods, you can alter your metabolism and shed weight.
Does it work?
“With the Atkins diet, carbs are labelled as ‘bad’ for us. But the problem is, we have a tendency to over-consume carbs which can be the cause of weight gain. If, as with Atkins, we eliminate carbs, it’s likely that we’ll lose weight (by taking in less calories than we use) but if continued over the long-term, we could suffer kidney problems. The body may also break down muscle protein,” says Schenker.
5. The F-Plan
The F-Plan diet is based on a high intake (40g) of dietary fibre a day. This includes fruit and vegetables, wholegrain bread, cereals, soups, salads, beans and pulses, as well as fish.
The theory
The idea is that by eating lots of fibre, you reach satiety point before you’ve eaten too many calories. Fibre also often passes through the system undigested, or at least takes longer to digest, offering bulk without the calories, keeping hunger pangs at bay. You’re also likely to excrete more undigested calories a day, therefore boosting weight loss.
Does it work?
“The F-Plan can certainly help with weight loss. There is however the risk of eating large amounts of bran, for example, which may cause bloating and can even lead to malabsorption of food (along with nutrients). Bran can also inhibit the absorption of minerals such as iron and calcium. For these reasons, the ‘Soup Diet’ may be a healthier (but with the same effect) alternative,” says Lazarides.