Reality: Obesity is more closely related to malnutrition than it is to excess energy intake!
It is important to distinguish between energy (represented in calories), and nutrients (fats, proteins, carbohydrates, vitamins, minerals, and many complex parts of food that we don’t label). Even though the human body is very capable of storing energy as fat, it only does so excessively when nutrient intake is unfavorable!
1. Appetite is regulated by hormones in response to nutrient deficiencies. When the body’s nutritional needs are not being met, it continues stimulating appetite, no matter how many calories have been consumed! If you are hungry, this means you are missing something. It’s not a good idea to ignore this, because...
2. Deficiencies encourage fat storage. We happen to be good at storing fat, but just because energy goes into the body does not automatically mean it will be stored (the so-called "calories in, calories out" theory). Rather, the body tries to achieve homeostasis, or equilibrium, at a certain level of fat mass (sometimes referred to as a “set point”) that is influenced by how healthy it perceives you to be. Over time, nutrient deficiencies lead to unhealthy tissue quality, which the body interprets to mean that food sources are not dependable; the body then increases its “set point” for how much fat it actually tries to store. In conditions of abundance and healthy tissue quality, the “set point” is geared to go down!
3. Low-fat diets encourage fat storage. Aside from how much fat the body thinks you need to keep stored, storing fat is also a direct result of your body trying to control blood sugar levels. When we try to reduce calories by shifting away from fats, we necessarily increase our proportion of carbohydrates, which increases the amount of fluctuation in our blood sugar levels. High blood sugar causes the pancreas to secrete insulin, which activates several response mechanisms to control it. The two most relevant ones are:
a. Adipose cells. These cells store fat, but their most important job is actually as a transformation plant. As long as blood sugar is elevated, they draw in glucose and convert it into stored fat, to reduce the blood sugar levels.
b. Muscle cells. These are the biggest consumers of caloric energy aside from the brain. In the absence of insulin, they use fat as their primary energy source (only letting in enough glucose to fill their small glycogen energy stores). But when insulin indicates blood sugar elevation, they will accept more glucose, and burn that instead of using up fat. (Muscles burning glucose has negative side effects, addressed later, which is part of why these cells tend to become insulin resistant over time.)
The solution to obesity is to supply the body with ample amounts of the nutrients it actually needs (more is better than less!). It is especially important to ensure that sufficient fat be included (>50% of total energy intake), primarily from animal or fruit fat sources (NOT grain, seed, or “vegetable” oils) in order to meet energy needs without excessive blood sugar fluctuations. This results in appetite being satiated, a lower fat mass “set point” based on healthy tissue quality, less adipose cell activity from blood sugar elevation, and a return to reliance on the preferred energy source (fat) of your muscle cells.
Also with regard to nutrient deficiencies, the foods which have become cheapest through our methods of agriculture and industrial processing are often the most nutrient-poor, which is also why obesity is most prevalent in poorer demographics and homeless populations. Because food is far more complex than we yet understand, it is not yet scientifically possible to produce processed foods which meet our nutrient needs; therefore it is extremely important to choose food sources that come from whole, natural ingredients!
Reality: Cholesterol is about quality, not quantity.
HDL (high-density lipoprotein) has historically been referred to as “good” cholesterol and LDL (low-density lipoprotein) as “bad” cholesterol, but this is incorrect. Both HDL and LDL are normal, useful, beneficial components of your blood profile. One of their most important jobs is to carry fat through the bloodstream, since fat is not water soluble. (As mentioned in #1, fat is your muscle cells’ preferred form of energy – what they would use if insulin did not tell them to do otherwise.) In addition, they play important roles in the immune system.
The problem begins when LDL particles, which are by nature supposed to be “low density” (also known as “large, buoyant” LDLs) are starved for actual fats (fat has a lower density than water) and thereby become dysfunctionally shriveled (referred to as “small, dense” LDLs). It’s these small, dense ones which are susceptible to oxidation (chemical reactions with oxygen); and oxidized LDLs are subsequently the ones which actually create the inflammation that contributes to arterial plaque. But by eating less fat and cholesterol (the tactics we use to try to lower our cholesterol totals) we actually reduce the quality of our LDLs, promoting the “small, dense” type, instead of big, fluffy, happy, fat-filled ones!
In addition, eating less fat means we eat more carbohydrates in order to meet our total energy needs. As mentioned earlier, this results in greater blood sugar fluctuations, causing insulin to be released, and encouraging muscle cells to use glucose for energy instead of fat. Unfortunately, this has side effects (which is why it’s not the default option in the absence of insulin), because burning glucose for regular muscle energy produces byproducts: reactive oxygen species (a type of free radical), which pose the threat of oxidation to unstable molecules and cells.
So by eating less fat and cholesterol, we encourage our LDLs to become small and dense, and susceptible to oxidation. And by eating more carbohydrates, we force our muscle cells to produce more reactive oxygen species. So in trying to reduce our cholesterol totals, we create the perfect storm for generating oxidized LDLs, the real catalyst for atherosclerosis!
The real solution here is to have enough fat, and of the right kinds. Especially saturated fat.
Reality: Saturated fat is not only harmless, but beneficial and necessary, and should make up a large percentage of your energy intake.
Fat does not pour into your arteries like grease going down the drain pipes in the kitchen sink. It is not water soluble, so it only reaches the bloodstream when carried in lipoprotein particles (which your body deliberately constructs, and which are good things). Saturated fat actually makes these cholesterol particles healthier (making your LDLs more of the “large, buoyant” variety), reducing the likelihood that they will become oxidized and contribute to arterial plaque.
Fat, the primary source of energy preferred by muscles, is also a key structural building block and has many, many important uses in the body. Nearly all mammals, after converting their natural food sources via their respective digestive systems, derive a majority of their energy from fat. This is true even for most herbivores. Although we are used to classifying vegetable matter mainly as being carbohydrate-based, vegetables and fiber typically get converted by gut bacteria into fat for use by the host animal. Gorillas do this in a 30-foot colon; cows do it with multiple stomachs; but humans, with our proportionally much smaller digestive systems, are built to perform best when we take in our preferred nutrients in the right proportions directly, which means to include a lot of saturated fat!
Not only is it not harmful, but increasing saturated fat intake actually can do a great deal to treat both obesity and diabetes, by meeting our energy needs while reducing blood sugar fluctuations. Increased fat intake means two important things: proportionally lower carbohydrate intake, and also a slowing of the metabolic processes that allow glucose to enter the bloodstream. Both of these factors considerably reduce the “glycemic impact” of a meal (the level of spike in blood sugar created).
This also results in less crashing after a sugar-heavy meal, and more consistent energy throughout the day. Since the body does not have to engage its mechanisms for dealing with blood sugar fluctuation and using up glucose, it can meet its energy needs through more reliable, sustained, fat-based methods. Furthermore, this gives muscle cells the opportunity to recalibrate from insulin resistance that they may have developed, making it an important way to treat diabetes.
Lastly, saturated fat should especially be used to replace omega-6-based fats. Omega-6 fats, a type of polyunsaturated fat, are the primary components of most “vegetable” oils (corn, soybean, safflower, sunflower, canola, and others). They cause inflammation and are not a preferred building block and energy source in the body. They have only become readily available through industrial processing techniques that were promoted on the basis of being cheaper, and because of the mistaken blame given to saturated fat for heart disease.