The USDA food pyramid suggests 6-11 servings of bread, cereal, rice & pasta, 3-5 servings of vegetables, 2-4 of fruit, 2-3 of dairy and 2-3 of meat, fish, eggs, & nuts.
Viewed from another perspective, that works out to 11-20 servings of carbohydrate and 4-6 of protein, with very little to no fat. You could also look at it as 8-14 servings of things you aren’t designed to metabolize and 7-12 servings of good stuff. (You could also look at it in terms of miles the food had to travel and/or gallons of fossil fuel burnt to deliver it to your table, but more on that in a later post.)
This is a little more balanced....
Anyway, here is a more appropriate food pyramid, one that is based on considerably more research, and isn’t influenced by large agribusiness interests. A couple of things to note. First, yes, there is sugar on this pyramid, despite the typical prescription excluding sugar. Just go easy on the sugars, and keep away from anything overly processed. Also notice that the serving sizes are left out. People are different and require different intakes in different proportions to function right.
Zone, Paleo or 100-Mile, try to eat foods that are not highly processed. ”Meat and vegetables, nuts & seeds, some fruit, little starch, and no sugar” will make a huge difference.
So how many of these giant 12,000 calorie gummi bears can I eat per day and still be safe?
http://blogs.sfweekly.com/foodie/2010/07/hey_east_bay_the_worlds_larges.php
Yeah, about sugar, starches, fruits… Carbohydrates are the only macro nutrient that can be completely eliminated from our diet. This is important point to remember. Our body only needs about a teaspoon of glucose and the only cells that actually need it are the red blood cells. Despite our love affair with sugar we’re not genetically adapted for it and the page long list of diseases and disorders linked to glucose toxicity makes the choice of eating sugars or not an easy one.
Or does it?
Our bodies have done some evolving around sugar I would think, else why would we have evolved tastebuds specifically to taste it and only four other basic flavor impressions? Quantity seems to be the problem, as with most things that are bad for you.
Matt, sugars were incredibly sparse in our past. Our ancestors, gatherers, learned that anything tasting sweet in nature was ok to eat, it wasn’t poisonous, hence the evolved taste buds. But, besides a bee honey few times a year maybe and, by today’s standards, very bitter fruits there was nothing else. Nothing that prepared us for the amount of glucose in our system today.
Thanks Branko. How long ago did we as a species see a large increase in the amount of glucose we consume, I wonder? New evidence is coming to light that humans can evolve more quickly than previously thought. For instance, some geneticists in Beijing recently discovered that Tibetans had evolved a gene as recently as 3,000 years ago to deal with low oxygen levels. Doesn’t help us as individuals, but does make me curious as to whether we have a greater ‘tolerance’ for glucose than our paleolithic ancestors did. Certainly we don’t have a tolerance equal to the amount most people consume today, but perhaps we’re able to tolerate more than our distant ancestors could.
Good question, MAtt. The sugars got introduced with “invention” of agriculture 10.000 years ago. To give you an idea just how poorly we’re adopted to sugars- we don’t even have a hormone that would directly deal with glucose in our bodies. When glucose is detected in the bloodstream our body needs to get rid of it fast because it’s so toxic. It stores it as fat and it uses 2 hormones as vehicles, liptin and insulin. We think of insulin as the hormone which task is the glucose metabolism but in reality that task is only marginal. Its role is much bigger, but since we have nothing else to deal with glucose it’s the only thing that our body has to remove the glucose. Our insulin levels are constantly elevated and the vicious cycle of hyperinsulinemia, insulin resistance and diabetes begins.
Interesting that we wouldn’t have adapted better. For instance, the southern Chinese discovered they could turn farmed grains into alcohol about 10,000 years ago too, and promptly (relatively) evolved a gene that helped break down booze quickly, with the side effect of turning their faces turning flushed and red.
I realize that’s not comparing apples to apples in any case.
Also keep in mind that most of the sugar that we eat today is heavily refined. It is only recently that refined sugar has been so available and present in just about everything. Definitely not something our body has adapted to. And never mind garbage like high fructose corn syrup.
Branko, I hate to call you out, but your statement isn’t entirely correct.
We humans, along with our ancestors and many other omnivorous mammals, have numerous mechanisms for dealing with sugars (and alcohols, but that’s another post entirely).
For example, we have an enzyme in our saliva, amylase, which breaks starches down into glucose.
Glycogen, one of the two anaerobic fuels in our muscles, is created from glucose.
Also, brain metabolism requires mostly glucose and does not function properly without it. If you stop eating carbohydrate, your body will begin to break down triglycerides stored in fat cells to keep your blood sugar levels up enough to fuel the brain. If your blood sugar drops to 40mg/dl, you will be pretty severely impaired, as the higher functions of your brain begin to shut down. 10mg/dl and you’ll be in a coma.
Anyway, your body doesn’t need a lot of sugar to function, but it does need some. The more raw the source, the better.
Nick, no problem. Diet is something i’m passionate about and love to talk discuss it anytime.
Humans have several hormones designed to raise glucose and only one to lower it. Carbs were so rare that there were no need for lowering it. We have the ability to hormonally raise blood glucose in emergency, which is, true, crucial for survival. 100mg/dl of glucose in our bloodstream is a norm, lower is more desirable. Not sure if you realize how little sugar that is. Say you have 5 liters of blood in your body, that’s 50dl x 100mg = 5g. Or, as i said, a teaspoon. Our body is absolutely adamant about maintaining the minimal level of glucose at any time, as it’s damaging to the vessels, organs and tissues. 1 small bagel has 6 teaspoons of glucose, 5 times the amount allowed in your blood stream!
Glucose in the blood auto-oxidizes, which produces free-radicals, that damage arterial walls. It also bonds with proteins (glycation) into AGEs. AGEs accelerate (appropriately) aging and cause DNA mutations. Aging is now being understood as a gradual process of tissue glycation of all tissues, including the brain. AGEs also bind with certain receptors in the blood called RAGEs that induce inflammation, leading to cardiovascular diseases…
That brain needs glucose is a myth. Our brain can run better on ketones, the energy units of fat. Ketones are much more steady and reliable source of fuel for our brains and organs. Also, brain cells are much less sensitive to insulin so glucose causes the most damage right in our brains. In fact, our brain shrunk 10% in last few 100 years according to some researchers. ADD/HD, learning problems, mood disorders, depression, alzheimer’s etc. are on the rise.
Again, ketones are much more appropriate fuel for us instead of glucose. From glucose you get a burst of flame, like with burning paper, which dies fast and you’re left with cravings for more. Ketones are, on the contrary, long burning sustainable energy. Our red blood cells, however, do burn glucose instead of fat, it has something to do with preserving their cargo- the oxygen and that’s why we need that little amount of sugar.
Hope that helps.
@Matt - Any adaptation due to evolution would require some selective pressure. Unfortunately the sugar issue generally doesn’t kill people very quickly. It waits until they have had a chance to breed, then kills them slowly. So there’s really no selective pressure, it just makes people miserable, and unhealthy over a long period of time.
@Roger Good point, though the diabetes epidemic among kids today may end up providing that selective pressure, sadly.
Branko,
I don’t buy the argument that we shouldn’t eat sugar because we are inefficient at metabolizing it (i.e. we only have one hormone to lower bloodsugar). We only have one chemical compound for transporting oxygen, too. And that compound, hemoglobin, will bind with carbon monoxide 400x more readily than with oxygen. That doesn’t mean that we function better breathing CO.
Natural selection doesn’t have foresight and didn’t “design” us for specific tasks. It’s only ever just good enough to get by. Our ability to process sugar works the same way it does in just about every other mammal, that we have the metabolic apparatus to process protein doesn’t mean it’s a better source of energy than carbohydrate. We are omnivores, after all.
Now, I’ll give you that the brain can use ketones for energy, but ketone metabolism has its own risks, such as ketoacidosis. Research would suggest that ketone metabolism in the brain is an evolutionary tool to help us survive prolonged fasts, but that doesn’t necessarily mean that it is a healthy alternative to a glucose metabolism.
Further, if you look at the diets of any hunter-gatherers– any animals at all, really– you’ll find that they gorge themselves on any available food when it’s plentiful. This includes high-carbohydrate items such as berries and roots. Again, because we have a metabolic pathway for dealing with a surge of blood sugar doesn’t mean it’s good for us. In the end, balance is going to be the key to maintaining a healthy diet.
So, don’t stress if you chow down on a bowl of ice cream or have a few beers every once in a while. Keep the rest of your intake sane and enjoy the fact that you’re an omnivore– one of nature’s metabolic generalists.