Several months ago, I wrote about how I was “retiring the ’80/20 Rule’” – the one where you eat healthy 80% of the time and allow yourself to eat less healthy 20% of the time. While the intentions behind this “rule” are good, I find that it doesn’t always help with “all-or-nothing”/perfectionistic type thinking. Some people have twisted the 80/20 Rule to mean, “I need to be 100% perfect during my 80%, so that I can go all out during my 20%.” Instead, it’s simpler and less triggering to say, “You don’t need to be perfect in order to be healthy.”

Here’s another “80/20 Rule” that needs to be thrown in the bin – that health is “80% nutrition, 20% exercise”

Why ‘80% Nutrition, 20% Exercise’ “Makes Sense”

Often the “80% Nutrition, 20% Exercise” phrase is used in the context of weight loss. Ignoring the fact that there is currently no 100% safe, effective, reliable and sustainable method of permanent weight loss, and that equating weight loss with improved health is problematic, evidence shows that exercise alone is an ineffective strategy to lose weight.

I used to love this YouTube video that illustrated this idea of “you can’t outrun your fork” – in it, there are two men – one is running top speed on a treadmill, while the other is eating pizza and drinking pop. As the guy running on the treadmill is huffing and puffing away, periodically announcing the calories that the treadmill states he’s burned, the guy who’s eating the pizza and pop shares that he’s already eaten many times that amount of calories, in the same few minutes.

Even without this extreme example, think about how often we eat versus how often we exercise – most of us eat at least three times a day, while exercising much less than that.

Why ‘80% Nutrition, 20% Exercise’ Doesn’t Actually Work

Our society tends to lean heavily on this idea of “personal responsibility” and “lifestyle change” when it comes to health. This fuels a lot of weight stigma and fatphobia—the idea that people in larger bodies have “done this to themselves”, and that there’s something “bad” or “wrong” with them if they’re not trying to lose weight or “be healthier”. This is textbook healthism, or placing a moral value on the pursuit of health.

In reality, we have much less control over our own health than we think. Though the exact figures are unknown, the CDC estimates that social determinants of health, like discrimination, income, living environment and access to health care, account for about 75% of our health, while health behaviours account for only about 20%. In other words, even if the “80% Nutrition, 20% Exercise” statement were true, it would really actually be “16% Nutrition, 4% Exercise”.

So, Does That Mean I Should Just Give Up on Being Healthy?

I know it seems counterintuitive for a dietitian to downplay the impact of food and nutrition on health. I mean, don’t I hold the “secret”? Shouldn’t I be the first to believe that nutrition cures all?

The point of this article is not to give up on eating your vegetables – everything counts.

Instead, I would say the take-home messages of this post are three-fold:

1. Cut yourself some slack when it comes to health. Food, water, exercise, sleep, etc. don’t deserve that power.

There’s no such thing as a perfect diet, and even if we somehow discovered what it was, I highly doubt it would be the answer to cheating death. Sure, engaging in health-promoting behaviours can make us feel better, but it can also make us feel worse mentally when we take it to extremes. We only have one life – why spend it counting calories, obsessing about what’s in/not in your food, or stressing about whether you’ve “done enough” when you can just enjoy it?

By the same token, there is no single food that is going to cure cancer, pay your mortgage and guarantee a long and disease-free life. Food is food. While some foods are associated with better health outcomes than others, there are so many other factors that play into health – you are not a “bad” person if you eat less nutritious foods, nor is there some miracle food that will solve all of your problems.

2. If health is a priority, we need to put more focus on social determinants.

Many public health initiatives, like posting calories on menu boards or banning all drinks except water from public schools, are at best band-aid solutions or window dressings, and at worst doing more harm than good. If we really care about health (and I should note here that it doesn’t make you a bad person if you don’t), then we need to do more work in reducing poverty, fighting for equality and improving access to care.

3. Let’s stop it with the 80/20 Rules, ok?

So far, we’ve debunked two 80/20 Rules – NEXT!