Macronutrients vs. Overall Diet: Which is More Important?

It's an axiom among dietitians that "people eat food, not macronutrients." That's one of the reasons that we find fad diets to be so silly: so many of them demonize entire classes of foods ("all oils are bad," "avoid all carbohydrates," "don't eat animal products"). While there are those who may find these diets work for them, the vast majority of people can't live with those diets for the long term.

The good news is that following a Mediterranean-style diet is easily sustainable for the average American (as well as the rest of the world). No foods are considered "bad," or off-limits, although certainly some foods are to be eaten less often than others. For example, although red meat should not be eaten nearly as often as fish, that doesn't mean you shouldn't eat it at all: having a steak once every couple of weeks is fine. (Read more about the 9 principles of the Mediterranean Diet.)

A recent study performed in Sweden (AGE 2011;33:439-450) looked at the diets of over 1,000 men and women who responded to a detailed dietary questionnaire at the age of 70. The researchers were able to assign a 9-point Mediterranean Diet score to each participant, with a higher score meaning a better adherence to Mediterranean Diet principles. They were also able to analyze each person's diet with respect to macronutrients such as total carbohydrates, fiber, and saturated and unsaturated fats.

Using Sweden's centralized medical records system, the researchers were able to determine death dates and causes for those participants who diet over the course of the study, which lasted an average of 8.5 years for each participant. The scientists were then able to analyze the participants' overall mortality (their risk of death from any cause) with respect to not only their overall Mediterranean Diet score, but also with respect to the levels of macronutrients in each person's diet.

They found, even after allowing for such variables as overall caloric intake, age, gender, whether they smoked, or risk factors for heart disease such as cholesterol scores or Body Mass Index, that there was no significant association between levels of protein, fat or carbohydrate intake and a participant's risk of death from any cause.

On the other hand, in line with other studies, they found that a Mediterranean Diet score of 6 or above reduced a participant's risk of death from any cause by 18% when compared to those with a score of 5 or below. Interestingly, this held true even when the participant required assistance with activities of daily life or were otherwise functionally impaired due to their age.

What this means for you

It's clear that worrying about how many carbs you eat or whether you eat any fat is not a strategy that's going to prolong your life. Instead, focus on eating great food, with an emphasis on more vegetables, legumes, fruits and nuts and whole grains, while eating more unsaturated fats than saturated fats and more fermented dairy (such as yogurt and not milk), eating less red meat and leaner meats, and drinking moderately. You'll be eating well and eating healthy, while living longer.

First posted: December 28, 2011