A recent Time Magazine cover story about America’s “War on Fat” is very instructive about both human and pet nutrition. The title of the article, “Don’t Blame the Fat” says it all. In the late 1970’s it was determined that dietary fat and cholesterol were responsible for the high incidence of heart disease in America. By 1980, the war on fat was on and Americans were encouraged to eat less red meat and more carbohydrates. Very soon “Fat-Free” foods flooded the supermarkets. Like the good little soldiers we are, Americans followed orders and ate less butter, eggs, and red meat and more margarine, cereal, and pasta.
As a result of this giant nutrition experiment, Americans got fatter and sicker. Today, cardiovascular disease is still our number one killer, 1/3 of Americans are obese, and the prevalence of Type 2 diabetes is up 166%. The article reveals that the basis for the war on fat was a study that was badly flawed.
In the 1950’s and 60’s heart attack rates were increasing in the US. A Dr. Ancel Keys theorized that high levels of dietary fat increased blood cholesterol which clogged the heart’s arteries. He traveled the world studying the diets and heart disease rates of varying cultures. His landmark “Seven Countries Study” found that people who ate diets low in saturated fat had lower incidents of heart disease – just as he suspected. This study, which has been referenced close to a million times, became the foundation for a body of work that implicated dietary fat as the cause of heart disease.
Unfortunately, Dr. Keys cherry picked his data. He left countries that did not fit his paradigm out of the study. So, populations that consumed high fat diets and did not have high levels of heart disease and those that ate low fat diets and did have a lot of heart disease were conveniently swept under the rug. Dr. Keys saw what he wanted to see. And Americans have paid the price for this biased research. It is amazing how junk science can become nutrition dogma.
Recent research shows that there is no link between dietary saturated fat and heart disease. It turns out that the simplistic idea that fat in your diet gets converted directly to fat on your hips and heart is not how things work. In reality, excessive carbohydrates are a bigger problem. When carbs are eaten, by humans or animals, the pancreas releases insulin to shuttle the resultant blood glucose into cells for energy. When there is more glucose in the blood than the body can use at the moment, insulin helps convert the glucose to fat and facilitates its storage in fat cells.
Also, because carbohydrates are quickly converted to glucose, and insulin is fast to remove the glucose from the blood, we promptly become hungry again. This leads to over eating. That’s how dietary carbs make us and our pets fat. Not only that, but the high levels of blood insulin caused by excessive dietary carbs causes the body’s cells to become resistant to insulin. This leads to diabetes – a common disease in both people and pets.
Like a nasty weed, once it is established, diet dogma is tough to eradicate. The Time Magazine article concedes that not all human nutrition experts are ready to abandon the war on fat. Similarly, conventionally minded veterinary nutritionists cling to the notion that dog and cat food needs to contain lots of carbs. And the obesity epidemic continues even though we know better.
Are you watching your pet’s carbs?