In the book titled 'Trick and Treat: How Healthy Eating Is Making Us Ill', author Barry Groves claims that healthy eating can sometimes fail to keep an individual hale and hearty.
"Most people are eating in a way that is unnatural to us as a species," the Telegraph quoted Barry, who holds a doctorate in nutritional science, as saying.
"We're a carnivorous species - our gut is identical to that of a big cat. Yet we're encouraged to eat foods that have been padded out with modified starch and vegetable oils, and complex carbohydrates such as bread, pasta and rice, which have all been labeled healthy - but not the fatty meat that our body actually recognizes," he added.
He said that's the reason why we don't know when to stop eating.
"Try to eat too much fat - cheese, say - and your body will quickly tell you when it has had enough. But when you eat processed, 'low fat' food, your body never gets the message it has had enough, so doesn't tell the mind it is full," he said.
Previous studies on rabbits have shown that eating saturated fat would lead to heart disease. This is because, Barry says, the rabbits were fed unnatural diet.
"The first, in 1950, showed that if rabbits were fed a cholesterol-rich diet, it would fur up their arteries.
"Yet, rabbits are only designed to eat plant life, which has no cholesterol. The clogged arteries were caused by feeding them an unnatural diet. It could have been an allergic response.
Taking about the other tenets of a healthy life - five portions of fruit and veg, wholegrain cereals, soya milk, low-fat yogurts, he said, "Vegetables are not the problem but there's no biological or chemical reason to eat them. Liver, for example, has all the minerals and vitamins we need," he added.
"But fruit? The natural sugar it contains - fructose - is much more dangerous than simple glucose or table sugar. It has been linked to the rise in obesity," he added.
He also revealed that wheat collects bacteria and dirt as it grows, and is impossible to clean. Then stored in silos, it is a haven for mice and rats, so it gets sprayed with insecticides. Put a wheat flower under the microscope and you'll see traces of rat faces," he said.
Soy milk is made with unfermented soya beans - "highly dangerous," claims Barry. As for yogurts made with skimmed milk, they "lack conjugated linoleic acid, which prevents cancer".
For healthy eating he advised, "eat purer foods, and ones that are more natural to us as a species. Cut down on bread and eat more fish, eggs, butter - any animal protein, anything that used to move around, that wasn't stuck in the ground. Liver, kidneys, snails - even insects will do."