The saturated fat debate should have a been a non-starter, and probably would have been if people had the internet in the 50s, 60s and 70s when the science was done.

About a century ago, humans dramatically started changing their diet, notably with the introduction of refined sugar and vegetable oil (often processed into hydrogenated or trans fats). Ancel Keys, and the saturated fat researchers came up with the "lipid hypothesis", that fat sticks to the arteries and "clogs them up". They didn't even consider the new foods introduced when human health declined, but decided that it was something that we've always eaten which must be the problem. The reason people started suspecting cholesterol was because we'd just come up with ways of measuring it in the blood - so they took the data and went looking for "problems". It really didn't make any sense.

To quote Nutrition and Physical Degeneration, "Statistics have been published by the Department of Public Health in New York City which show the increase in the incidence of heart disease to have progressed steadily during the years from 1907 to 1936. The figures provided in their report reveal an increase from 203.7 deaths per 100,000 in 1907 to 327.2 per 100,000 in 1936. This constitutes an increase of 60 per cent. Cancer increased 90 per cent from 1907 to 1936." This is where things really started going south for humans, and cancer, arthritis, alzhiemer's, heart disease and diabetes really started to come into the picture. We have managed a continued increase in degenerative disease over the last 70 odd years since then. Today 1 in 2 persons who live to old age will die of cancer. Humans used to be able to live to that same age and have a 1 in 1000 chance of dieing of cancer.

Saturated fat is present in ever increasing quantities the closer you approach the equator. It's better suited to plants in warmer climates, as you move to the poles, polyunsaturated fat becomes more present since it has a lower melting point. Humans evolved in temperate regions, where saturated fat is more present. There are a number of studies done on natives eating high-saturated fat diet who were disease free (The Masai for example).

Today we have hypotheses (based on information we've learned since the "lipid hypothesis" about how fats work in the body) that PUFAs might be deterimental, since we know they go rancid easily. Over consumption of PUFAs in conjunction with an anti-oxidant poor diet and a diet low in saturated fat (combing saturated fat with PUFAs makes PUFAs dramatically more stable from rancidity), means that these fats can go rancid in the blood stream - when these happens these fats can no longer be used as fuel, and the immune system needs to clean them out. Many PUFAs (corn oil is the worst) are also higher in omega-3 and low in omega-6, humans have eaten extremely varied diets, but one constant is the ratio between omega-3 and omega-6, because of this constant, these fats are used as inter-cellular messengers for ramping up inflammation or turning inflammation off. Eat a diet of only omega-6 and no omega-3, and silent inflammation turns up in the body and becomes a constant drain on the system.

Still, I don't think that we will find any one fat sub-type as a true "enemy" (sat/mono/pufa - not counting fats destroyed by processing and unusable by humans for energy like hydrogenated and trans fats). All kinds of organisms use a mix of different fats, it doesn't make sense that animals would convert one type of fat to another in the liver, if that fat was harmful to them.

There is a debate, but it's sugar, alcohol and refined carbs make people fat. The liver can convert carbohydrates to fat. In fact, if fructose is consumed (which is 50% of the ingredients in table sugar), the liver has no choice but to convert it entirely into fat (and a really bad fat at that). Well, the first bit of fructose your body eats in a day can be turned into glycogen, maybe 10-80 grams depending upon your activity level, etc. But generally if you drink a can of pop, or a glass of fruit juice, it's all going to be turned into bad fast by your liver.

See Sugar: The Bitter Truth for more details on how refined sugar is just as harmful on your liver and on your body as alcohol.

With mayonnaise made from real olive oil and good quality eggs, it's a healthy food. There is no need for moderation when eating healthy foods. It just leaves less room for junk food. If a human limits themselves to healthy food, their mechanisms of hunger won't get all screwed up, like consuming refined sugar does to people. You can be relatively sedentary and never count calories and there is no way that you are going to become obese. Looks at tribal populations around the world, especially those near the equator where food is abundant - one example is the south pacific the kitavans - they don't have any obesity among them and they don't do too much exercise.

The brain is primarily made out of fat, and needs large amounts of fat to maintain brain cells. Eating low-fat deprives the brain of the nutrients it needs, which in many people manifests itself as a strong feeling of depression. Most vitamins and minerals are fat-soluble, that means we can only absorb and use them if they're consumed with fat. Lots of tribal cultures consume copious amounts of fat (Inuit), but they never get degenerative diseases such as diabetes or heart disease.

Real mayonnaise is made out of olive oil and pastured eggs. Both are very high in vitamins, minerals and good fats. Mayonnaise in the grocery store is made with canola oil or soybean oil, these are bad fats - they are very inflammatory and promote heart disease. In addition, they are made with caged-chicken eggs where the chickens are fed a nutrient poor diet. This means that there is a small fraction of the amount of nutrients that is in real mayonnaise. You can find mayonnaise such as "Hellman's Real" with a big photo of some olives on the front, promoting the fact that it, "contains olive oil", but it's mostly still canola oil with just a small amount of olive oil added to it.

"Saturated fat is bad" is entirely political. The US Gov't has literally spent billions of dollars on studies trying to prove the deleterious health effects of saturated fat. This started in the early seventies, and after they did a massive study, and with lots of lobbying from the grain-industry, politicians aren't going to come out and say, "We were wrong". Politicians aren't very good at saying that.

(Gary Taubes covered the history of low-fat in Good Calories, Bad Calories in great detail).

Saturated fat is a healthy fat, there is no reason to avoid it. Tribes in the Pacific eat a tonne of coconuts, and they live to ripe old ages, but they get better than 10 times fewer degenerative diseases than North Americans. They never get diabetes, they don't get alzheimers, they don't get arthritis, and cancer is very rare. Yet they eat a tonne of saturated fat.

They don't eat and sugar, grains or vegetable oil. These are the foods that make us sick and cause our bodies to degenerate prematurely.

The only animals that eat grains in nature are birds and mice. If you feed a cow grains, it will make it so sick that dies in a year or two. There is lots of proof showing that the contents of grass-fed beef is far healthier than grain-fed.

Turns out that high-fructose corn syrup is really quite bad for us. We haven't stopped making that. It's really naive to think that because a food has negative health effects on the population that people will stop making it.

It's the trans-fats in potato chips which are bad for you. Saturated fat has a neutral effect on blood cholesterol levels. But mostly it's the starch in the potatoes which causes the raise in triglycerides which far and away causes the most damage to a persons blood cholesterol levels. And eating "cholestorel-free eggs" is unhealthy, you'll be missing most of the nutrition from the eggs - eating whole eggs have a positive effect on your cholesterol (see Jimmy Moore interviewing the Eades about an 88-year old dude on an all-egg diet), they only raise the "good cholesterol" - it's sugar and starches which raises the "bad cholesterol". If it's "fat-free" then it's probably very bad for your cholesterol.

This study didn't fare well under close scrutiny, it wasn't well-done. ArsTechnica investigated it further and critiqued it fairly well. Which doesn't put HFCS off the hook, but regular table sugar is still extremely damaging on any animal that consumes it!

Yes, the topic of food addictiveness has been studied a lot and is well understood. It's the sugar which causes the dopamine release, and the sensation of pleasure. Fat enhances the absorption of the sugar - fat enhances the absorption of any food it's consumed with. Take away the sugar and leave a high-fat only diet and there is no addictive overeating problem. Take away the fat and leave the sugar, and there is the same problem, it's only marginally less pronounced. The headline is entirely misleading - but expected, people with sugar addictions often blame the "fat content" for their problems, they can't face their addiction head-on.

Agave syrup is just as heavily processed as HFCS. It's also got a higher fructose content than HFCS. Agave syrup is worse than HFCS.

Kind of. Fruit is something that should generally be consumed in moderation (1 to 5 servings per day). But fruit also has fairly low amounts of fructose in comparison to most HFCS food products. For example, fruit juice or soda pop are equivalent to eating 8-14 servings of fruit in terms of fructose consumption. And people can have many cans of soda pop in a day. The liver will convert fructose into glucose until the liver's glyocgen stores are topped up - depending upon activity levels, physiology and which scientists/nutritionist you listen to, this is anywhere from 10-80 grams per day. Any fructose consumed beyond a full store of liver glycogen, and the liver turns the fructose into really nasty crap.

In terms of human evolution, it wasn't until the last one hundred years when we were able to consume fruit year round. Furthermore, we've selected for fruit which is sweeter, and higher in fructose content over the years. Today's apple can have 3 times the amount of fructose that apples consumed a hundred years ago. We simply don't have the mechanisms in our liver to deal with significant quantities of fructose.

Yes, people here are also saying that there is something wrong with the study, see ArsTechnica's take on it. It was a poorly run study. The tip off that it was a poorly run study is that the Princeton article on the study suggests that factors such as the bond between fructose and glucose could be accounting for the significant difference between HFCS and sucrose.

Agave nectar is worse than HFCS. It has a lower glycemic index because it has a higher fructose content. The fructose is converted to bad fats directly by the liver, so there is less of a blood sugar spike, but the triglycerides created in this process is worse than a blood sugar spike.

http://www.westonaprice.org/Agave-Nectar-Worse-Than-We-Thought.html

Yeah, I've looked at my local Whole Foods for HFCS. It's in many of their salad dressings and barbecue sauces they carry. Although to be fair, there are more trace amounts of HFCS, they don't carry things like HFCS-sweetened bread. However, they do stock and sell agave nectar syrup (and market it fairly aggressively as end-cap displays) and agave nectar syrup is even worse than HFCS.