How We Get Fat
"Why We Get Fat" is a fascinating read and a very informative book written by Gary Taubes. Taubes, an investigative journalist, in his book, "stand the received wisdom about diet and exercise on its head". Taubes goes back through the history of the study of obesity and finds that prior to WWII, scientists had a very different view on what caused obesity; he goes through study after study, but finds no support for the current theory of cause for obesity. The current theory is base on what seems to be solid logic, that you get fat by eating too much or exercising too little, but he explains how the current wisdom is really just begging the question. We get fat (take in more calories than we burn) by eating too much (take in more calories than we burn). Our bodies are designed to regulate themselves. We only get hungry when we need more energy. So the real question should be why do we eat more than we need.
In the second part of his book, "Adiposity 101", Taubes explains the biology behind obesity, or getting fat. In short, the whole process is driven by insulin levels, which are driven by carbohydrates. Insulin is the primary hormone that regulates the fat tissues. Insulin is secreted by the pancreas. Eating carbohydrates causes a spike in blood sugar, and the body deals with the spike by secreting insulin into the blood stream. When insulin levels are raised, fat cells will take the fat in our blood stream (and sometimes converting carbohydrates into fat molecules) and store it away within the fat tissues. The insulin also causes other cells to stop using fat as fuel (the favored source of energy) and begin burning the carbohydrates. If you are continually eating too many carbohydrates, especially simple carbohydrates, your body will continue to store its fat, instead of using it as fuel. So, though you may still have plenty of energy stored in your fat tissues, it's stuck their until your insulin levels are lower and it is released. But the news gets even worse. Cells become insulin resistant. The more cell are exposed to insulin, the more the cells become insulin resistant. Fat cells are the least effected. To deal with this resistance, the pancreas pumps out more insulin, causing the fat tissues to store more and more fat. This results in a harsh cycle: the more carbohydrates you eat, the fatter you get, the more easily you get fat.
On the other side of the coin, Taubes looks at fat and reveals how it is, strangely enough, not at all the cause of obesity. In fact, he shows them to be very healthy, even heart healthy. In short, fatty foods are not fattening foods, but are quite healthy for you.
Taubes has thoroughly convinced me that fat is not the culprit to being fat, but I believe he has understudied one area, and thus misrepresented it. Though he cites much data and many studies, he fails to differentiate between different kinds of fats and different kinds of carbohydrates. He deals more fairly with fats, actually discussing effects of different types of fats, and to his credit, he does clarity that trans-fats are unhealthy. But he completely fails to do this with carbohydrates. He does, every so often, clarify that simple carbohydrates are worse, but I don't remember him ever mentioning complex carbohydrates by name. None of the studies he cited differentiated between simple and complex carbohydrates, thus we really cannot know if complex carbohydrates are really fattening.
Taubes shows a grave error in his thinking: evolution. He uses this standpoint to assert that the human race has been living off meat for hundreds of thousands of years and that only until very recent times have humans cultivated carbohydrate-rich foods. He concludes that humans did not evolve in such a way as to allow the consumption of large quantities of carbohydrates. The Bible clearly teaches to the contrary. It seems that ever since Adam and Eve were kicked out of the garden, humans have been cultivating grains. After the flood, there were many people groups who were "hunter-Gatherer"societies, but many too were farmers. I doubt the ancient Egyptians were obese or even slightly fat. Because of this, I do not accept that all carbohydrates are fattening, but rather only simple carbohydrates are fattening. This matches up with the history of obesity quite nicely. The obesity epidemic has exploded at the same time that simple carbohydrates--refined flours and sugars--have become a main part of our diet.
Taubes may be right that when dieting and trying to lose weight, the exclusion of even complex carbohydrates may be very helpful. Again, this cannot be discerned from his book due to the lack of differentiation between simple and complex. Still I found it a fascinating read, and would encourage anyone who wishes to understand basic nutrition on fattening to read "Why We Get Fat".