Back while I was writing about fats, I found an article on Food Politics (Marion Nestle’s site) about saturated fat. Since then, I have turned one of the quote over in my mind quite a bit. Within the article Nestle quotes Harvard’s Doctor Frank Hu:
The single macronutrient approach is outdated…I think future dietary guidelines will put more and more emphasis on real food rather than giving an absolute upper limit or cutoff point for certain macronutrients…people should try to eat foods that are typical of the Mediterranean diet, like nuts, fish, avocado, high-fiber grains and olive oil.
That stuck with me–the idea of a food-based guideline. But what is a food-based guideline? And what is the opposite–the nutrient-based guideline?
A Short History of Dietary Guidelines
The USDA has produced guidelines for nearly a century (which is weird in itself–why not have the FDA produce these guidelines?) and mostly the food-based type. Way back in 1916, the USDA began issuing food guidelines with “protective foods”. By the 1970s, the guidelines included the “Big Four” (fruits and vegetables, grains and bread, milk, and meat/proteins), but it wasn’t until 1979 that the USDA began to inform the public about the evils of fat and sugar via food pyramids.
In 1992, the Food Pyramid that I will always see when I think of USDA Food Guidelines arrived on the scene. According to the USDA, it focused on variety and moderation and tried to demonstrate portion sizes. It also included some information about fats and added sugars (trying to encourage low-fat, no added sugar eating patterns in Americans). This would be replaced with MyPyramid in 2005–the first interactive and customized dietary guideline. In 2010,MyPlate, another personalized dietary guideline replaced the iconic pyramid .
Each of these guidelines appears to be based on food, right? I mean, it tells you how many servings of different food groups to eat. So why is the good Doctor complaining? There is actually more to the story: Recommended Daily Allowances.
A Guide to Guidelines
Pull out a food item and look at the Nutrition Facts Label–any sort of packaged, processed thing will do.
If you look at the little guide above with the annotations or the one in your hand, you will see something very interesting–the percent daily value scale all the way to the right. The nutrition facts label and the Recommended Daily Values (in the footnote in the image above) are a great example of a nutrient-based guideline.
Nutrient-based guidelines focus on percentages (you should be getting X% of calories from carbs, Y% calories from proteins, and Z% calories from fats, which translates to x grams of carbs, y grams of protein, and z grams of fat for your caloric needs) and weights (miligrams of specific micronutrients). I like to think that this is where a phenomena I call the Multivitamin Fallacy comes from. There is a strange superstition that if you take your daily vitamin, you are pretty much golden–you are getting all sorts of healthy stuff, so you don’t need to worry about getting it from food. This way of thinking is a) wrong and b) divorces nutrients from foods (which is wrong in the other sense of the word).
One important aspect is that we don’t break down pills and real food in the same way or use the same nutrients from different sources interchangeably (necessarily). There best example of this is the beta-carotene study with smokers: knowing that beta-carotene from carrots was supposed to be protective against lung cancer, smokers were given beta-carotene supplements. However, instead of helping, it hurt the subjects in the experimental group and the study was stopped long before it was meant to end. I wrote about this a bit here.
Part of the reason we can’t just pop a multivitamin is that covers everything (and does it well) is that we just don’t know enough about nutrition and the makeup of foods (really, we don’t–that is exactly why nutrition is so confusing). Because of that, we simply can’t try to create a substitute food completely from scratch and expect it to have the same nutritional value–we don’t know what went into making the real food in the first place!
On the other hand, food-based guidelines (like Brazil’s standards, as Marion Nestle covered) tend to give the sort of advice a normal human would give (eat more vegetables, go easy on the fast food, etc.). Not only do they discuss food, but guidelines like this might suggest eating habits–prepare your own food as much as possible, eat with others, and eat regularly (all paraphrased examples from the Brazilian standards).
The Diabetic Food Exchanges System is an example of a food group sort of dietary recommendation: foods are broken up into food groups and serving sizes are determined using nutritional data (nope–you can’t get away from nutrition completely in a food-based nutritional guideline). Based on your caloric needs, you then find out how many servings you can have daily from each group.
By clearly suggesting whole, fresh foods, dietary guidelines can help people to make more informed choices. I remember when Weight Watchers changed their program to PointsPLUS–one of the changes was that fruits now had zero points. I can’t find the article now, but back then I read that part of the reasoning was that when confronted with the choice between a bag of processed chips worth 1 point and an apple worth 1 point, most people opted for the chips. I think that a food-based guideline has the potential to make people healthier just by clearing out all the misinformation that processed foods can be “healthy choices” instead of merely focusing on fat-intake and cholesterol (or whichever nutrients are currently infamous).
To Sum It Up
Food-based Guidelines: a nutritional guideline or standard emphasizing foods or food groups, servings and serving sizes, and healthful eating patterns.
Nutrient-based Guidelines: nutritional standards based on calorie intake and the proportion of that which should be made up of carbohydrates, fats, proteins, and alcohols, as well as recommendations of specific micronutrients like vitamins and minerals.
As a little food for thought, here are the ten Brazilian guidelines, excerpted from Food Politics:
- Prepare meals from staple and fresh foods.
- Use oils, fats, sugar and salt in moderation.
- Limit consumption of ready-to-consume food and drink products
- Eat regular meals, paying attention, and in appropriate environments.
- Eat in company whenever possible.
- Buy food at places that offer varieties of fresh foods. Avoid those that mainly sell products ready for consumption.
- Develop, practice, share and enjoy your skills in food preparation and cooking.
- Plan your time to give meals and eating proper time and space.
- When you eat out, choose restaurants that serve freshly made dishes and meals. Avoid fast food chains.
- Be critical of the commercial advertisement of food products.
Next week, I plan to have part deux out: In Defense of Food-Based Guidelines. Between now and then, please sound of in the comments about which you think is better and any arguments you have for or against!