The Caveman and The Avocado: Figuring Out the Diet Paradox

I just blew up one of my old mcmanweb articles on eating right, and replaced it with a new one. Following is an edited extract:
 
A 2003 journal article concluded that "the combined decline in mental health and the disappearance of traditional diets in circumpolar peoples makes a direct connection between diet and mental health in these people a very real possibility."

So, should we return to the diet of our ancient ancestors? Funny you should ask.

The Caveman Diet

A Jan 10, 2010 article in the New York Times describes a small tribe of city dwellers eating as they imagine their paleolithic ancestors did. The emphasis is on grass-fed (preferably wild) meat and seafood, nuts (but not peanuts), and berries. No grains or legumes. Advocates of the diet (there are at least three books out there) insist these are the foods we were built to eat.

According to an article published in the New England Journal of Medicine in 1985, the "diet of our remote ancestors may be a reference standard for modern human nutrition."

Prior to the advent of agriculture some 10,000 years ago, males stood at five feet ten and a half inches (179 cm). With the advent of agriculture (and with it novel foods), males shrunk five inches. Granted, the life expectancy way back then was about 25 years, but Fred and Wilma Flintstone weren't dying of the things we are dying of today, and they probably weren't as depressed.

Vegan and Vegetarian Diets

The very opposite of the caveman diet would be ones involving strict or loose taboos on animal products. Strangely enough, although the caveman and the vegan have very different concepts of what type of food is good or bad for you (meat vs agriculture) both shun many of the same foods, such as dairy products and refined sugars.

The principle of vegetarianism dates back to ancient times, but its widespread practice is fairly modern, based in large part upon our regard for our fellow sentient beings. And, oh yes, vegan and vegetarian diets are good for you.

Agricultural produce looms large, and saturated fats are avoided. Smart use of legume and grain combinations easily provides the full range of protein normally found in meat and seafood.

The Mediterranean Diet

The catch to eating like a caveman or a vegan is most people find these diets very difficult to stick to. They also raise alarms over the elimination of entire food groups, such as meat and agricultural products. Eating like a Greek or Southern Italian peasant, on the other hand, involves far less extreme culinary course corrections.

Meat and agriculture share the same dish, along with dairy products such as yogurt. The emphasis is on meat and seafood in low quantities, supplemented with grains and legumes such as rice or lentils. Olive oil is the main source of fat, and wine serves as an antioxidant kick.

Various studies attest to the health and mental health benefits of the Mediterranean Diet.

The Atkins Controversy

The Atkins Diet has been around for some 40 years, but until about ten years ago it was considered a quack diet, completely at odds with medical received wisdom. But a funny thing happened: People kept losing weight on it, thereby challenging the prevailing notion that we should be eating more carbs and less meat.

The diet features such offerings as bacon cheeseburgers, but nothing made from flour and hardly any vegetables.

A June 7, 2002 Sunday NY Times article, What if It's All Been a Big Fat Lie? raises this paradox: Fat-free carbohydrates, which digest quickly, may make us hungrier and inclined to eat more while fatty meat, which takes longer to digest, may keep us sated and less prone to over-eating. Indeed, this was the prevailing expert opinion, well into the 1970s, before the great cholesterol scare.

Yes, a Porterhouse steak may raise cholesterol, but not all cholesterol is bad.

Meanwhile, as carb consumption increased over the 1980s and 1990s, so did the incidence of obesity. The reason may have to do with the way our bodies burn fuel. Carbohydrate consumption switches on insulin. Insulin helps burn carbs for energy and stores fat for fuel. When insulin levels are low, we burn our own fat (a starvation-like but possibly natural state called "ketosis"). Too many carbs in the diet means fat stays stored rather than gets burned. There is also a risk that raised insulin levels may lead to "insulin resistance" and artificial hunger cravings.

A 2005 study comparing the Atkins Diet to the Ornish Diet (vegetarian), Weight Watchers, and the Zone Diet (emphasizing carbs) over one year resulted in similar weight loss in all the groups. A 2010 study comparing low-carb to low-fat diets over two years yielded much the same result.

The Avocado

Perhaps no food represents dietary confusion more than the avocado. A medium-sized avocado contains 30 grams of fat, about the same as a quarter-pound burger. Fat also equates to mucho calories (about 250 for an avocado). Because of all this, the avocado is a forbidden fruit on many eating plans, including the Ornish Diet.

But a 20-oz Coke also clocks in the same calorie count as an avocado. Seriously, is an avocado to be equated to a Coke?

Likewise, is the fat in an avocado comparable to a burger? Most of the fat in an avocado is monosaturated, the kind that lowers cholesterol. Indeed, a 1996 study found bad cholesterol (LDL) levels dropped in avocado-eaters while good cholesterol (HDL) levels climbed.

Meanwhile, the avocado is low in carbs and nutrient-rich, with more potassium than a banana and loaded with vitamins and minerals and antioxidants. Moreover, we all need fat in our diet, and if you are avoiding meat the avocado represents an obvious healthy alternative.

A similar case can be made for nuts (peanuts are technically a legume, but we can include them here), high in fat and calories but loaded with good stuff.

Wrapping Up the Food Debate

The obvious lesson from all this conflicting information is how adaptable we are to very different types of diets. If a high vege regime doesn't suit us, for instance, we have other choices. The other lesson is that it seems that those who stick to their diets - or at least stay with some kind of cogent plan - experience at least moderate success, regardless of choice.

We also see an emphasis on eating healthy and natural foods in moderate portions and staying away from processed and refined foods. This comes into play especially when we prepare our own meals (every diet plan comes preloaded with home recipes) where we control the ingredients that go into our mouths.

Finally, we begin to realize that smart-power is as important as will-power. Opting for a high-fat, high calorie food, for instance, may be a smart choice. It may also be a very dumb one.

Be smart. Eat well, live well ...

Based on: You Are What You Eat

Also on McManWeb: Diet and Obesity * Sweet and Sour *  Supplements and Natural Remedies * More on Supplements and Natural Remedies * Omega-3 for Depression