Here we are, at the end of the low-fat diet era. People are no longer dead-set against fats: we've selected a new enemy: carbohydrates. We have gotten fatter as a nation on the low-fat diet, because we have grossly over-compensated with carbohydrates to make up for the lack of fats. Now, in a typical over-simplification of the problem, we've declared war on carbs.
But let's back up a bit: what do carbs do and why shouldn't we go without them completely? The broad category of carbohydrates includes starches like pastas and bread; sugary foods and vegetables like green beans, beans, corn and potatoes; and also fruits. These groups are the main sources of fiber in our diet, as well as certain vitamins and minerals. They are also a good source of energy from which our body derives glucose, our preferred source of energy.
Metabolically, what happens when you don't consume enough carbohydrates is that your body starts to burn muscle and fat for energy. This forms what is known as ketone bodies and also some glucose. The negative effects of this are numerous. The first is that as your body uses muscle for energy, your metabolism gets slower, since the amount of muscle that you have is directly related to your metabolic rate. If you resume your original caloric intake with this slower metabolism, you'll actually gain fat.
Another problem with this type of diet is that using ketone bodies as a form of energy is not natural for the body. This causes migraine headaches, low energy levels, and a weakened immune system.
Lastly, this type of diet can not be maintained for any extended period of time. We all enjoy some carbohydrates and will eventually want to resume eating the way that we were previously, and will gain more weight back than we have lost.
So bottom line, there is one positive to this diet, which is that in the short term, this diet will indeed induce weight loss. The negatives far outweigh the positives as, eliminating carbohydrates causes low energy levels, leads to vitamin and mineral deficiencies, causes long term fat gains, migraine headaches and muscle wasting.
Why can't we embrace balance? Why must we always go to the extremes of diet? It's not the carbohydrates that are making us fat but the excess calories. If we just moderated the amount of carbohydrate rather than eliminating it, this becomes a very practical and healthy long term weight loss diet.
