Tuesday, August 27, 2013

Diet Myths: If a Little is Good, a Lot is Better

In the modern diet world, there are so many different theories and ideas on nutrition that it can sometimes be overwhelming. We have diets that don't allow carbs, diets that restrict fat, diets in which you eat exclusively fruit, diets in which you can't eat animal products, diets based on "superfoods"... whatever that means. Whichever food or food group is targeted, most of these diets fall victim to the same fallacy: if a little is good, more is better. Or, in many cases, if too much is bad, then none at all must be best.

Allow me to elaborate. Eating too many carbs can be detrimental, so restrict them all... too much dietary fat can be bad, so get it as low as possible... eating fruit is healthy, so let's eat nothing but fruit. You see the pattern? I don't think I need to go on. None of these diets get at the foundation of a healthy eating plan, and none come close to establishing a healthy relationship with food. What they lack is a sense of balance. Along with a misunderstanding of how biology works.

The U-Shaped Curve
Too much isn't good, but neither is too little. That is the idea of the U-shaped curve. Take, for example, this graph that I just found in a quick Google search...

See the U shape? This graph is a simple depiction of the relationship between sleep duration and risk of mortality. Those who get too little sleep have a higher risk of death; this is common sense. But does that mean we should get as much sleep as possible? Not exactly. People who get too much sleep also have a higher risk of death. The lowest risk lies at the bottom of the U; according to this graph, seven hours of sleep per night is associated with the lowest rate of mortality.

We see this type of U-shaped relationship in nearly every aspect of nutrition and biology. Too little water and we'll die of dehydration, but too much and we'll die of overhydration. Too little exercise isn't good, but working out for 8 hours a day isn't so great either. A little Snookie in our lives is good to instill confidence in ourselves and remind us that hey, at least we're not Snookie... but too much Snookie can lead to a hostile attitude towards others and a tendency to speak like a faux-Italian Jersey girl. See? The U-shaped curve applies to more than you realize.

Moderation and Balance
There's a time and place for total restriction of food groups, and I see that being most useful for people with serious medical conditions like food allergies. It can also be beneficial as a short-term cleanse type of diet for those who need a kick start to their healthy lifestyle. But that does not mean that any of these things should be taken to the extreme, nor do they need to be permanent or long-term. Just because reducing your carbohydrate intake may be beneficial for you, that does NOT mean that eliminating them entirely is even better. The same goes for grains, fat, sodium, sugar, gluten, meat, fruit, dairy, vegetable oils, etc. Balance is key.

When you're walking through Barnes and Noble and you take a glance at the diet section, just remember the U-shaped curve. There are very few cases in which this U-shaped relationship is not true, unless we're talking about straight up toxins like lead or mercury. Don't be gullible. Achieving health is never as easy as eliminating one food.

1 comment:

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