It all started with a NY Times article on obese monkeys.
Here is the question:
How did they make the monkeys obese?
It turns out that it was not complicated at all. They simply add some foods with two primary ingredients that have already been under suspicion. But when they combined them both, some fat magic happened.
Keep in mind that these are monkeys in cages. There are no "self-esteem" issues at play. It had nothing to do with "eating too much and not exercising enough". They did not select "couch potato" monkeys. They tried to induce the "couch potato" lifestyle on the monkeys, but it was the diet that tipped the monkeys into obesity.
All the monkeys were getting monkey chow which was about one third fat, (probably) 20% protein, and about 50% carbohydrates. That is the standard monkey chow every monkey gets and it does not usually cause obesity.
So how do they get these darn monkeys to be fat? They ADDED a peanut butter snack, a high fructose sweetened beverage, and occasional peanuts and popcorn. There are two factors that stand out about those dietary additions. Can you guess what they are? (Hint--see title of this blog).
The fats we get in our diet basically consist of three types:
Saturated fats are the stiff fats at room temperature and usually have a long shelf life. Common saturated fats would be lard, tallow, coconut oil, and palm oil. They are usually found in our diet from meat, dairy, chocolate, and coconuts.
Polyunsaturated fats are liquid at room temperature and even when refrigerated. They do not last long before going bad. They are usually kept stable and safe by adding preservatives or antioxidants. PUFAs are highest in seed oils like soybean, canola, corn, peanut, sunflower, safflower, cottonseed, grapeseed, and walnut oils. They are usually found in our diet from snack chips (or crisps in the U.K.), salad dressings and mayonnaise, crackers, cakes, cookies, popcorn, peanuts, corn, nuts, seeds, and whole grains.
Monounsaturated fats are also liquid at room temperature but can be solid if refrigerated. Common sources of high monounsaturated fats would be olive oil, macadamia nut oil, and high oleic sunflower (not to be confused with regular sunflower) oil. Common dietary sources of MUFAs would be macadamia nuts, maybe some Italian or Mediterannean foods, and some salad dressings.
So did the researchers add a high saturated fat snack to the monkeys' diet? No.
Did the researchers add a high MUFA snack to the monkeys' diet? No.
The researchers added a high PUFA snack to the monkeys diet. Did it work? Not well enough. Not until they added a high fructose sweetened drink did the researchers get the big fat monkeys. But fructose is not effective enough on its own to cause obesity. It takes BOTH.
PUFAs and Fructose
But how do we know it wasn't glucose (the other carb in the equation). Because the peanuts and popcorn already have carbohydrates that break down to glucose in them. But fructose is a different type of carbohydrate entirely. With fructose they had the key carbohydrate that worked with the key fatty acid and did a number on their systems to generate obesity.
PUFAs and fructose is a magical blend that may be the greatest discovery in this decade. With PUFAs and fructose you also may be able to generate diabetes, heart disease, and cancer! Four morbidities for the price of a little vegetable oil and sugar!
Time will tell.
Charles L. Peden