Green slimming

Some American nutritionists offer a very peculiar diet.
It should eat vegetables and fruits only green because these nutritionists are convinced that green promotes weight loss.
It is difficult to assert with confidence they are right or not, but that such a diet will not cause harm, for sure.
After all, green apples, kiwi, cucumbers, peppers, zucchini is very good for your health.
And yet it is believed that green vegetables and herbs have a negative calorie, ie organism spends its processing more energy than they carry.