Three Things I Learned About Why Diets Don’t Work, from a Registered Dietitian Nutritionist

1 – If You’re a Menstruating Woman, Intermittent Fasting Might Not Be for You

Scroll Instagram health hashtags, and no doubt you’ll see tons of posts about intermittent fasting, a process where people restrict their window of daily time during which they eat.

Fasting times range from 12 to 16 hours, which means people go that length of time without eating.

I’ve personally done intermittent fasting before, not to lose weight, but because I’ve found that I’m sometimes not hungry in the morning, so I simply wait for the impulse to eat, which usually happens between 13-14 hours naturally.

I had to ask Tamar about intermittent fasting for women, in particular menstruating women, because I’ve read famed hormone expert and Flo Living author Alisa Vitti say it’s actually potentially damaging for women who still get a period.

Here’s Tamar’s take on intermittent fasting for women:

“When we think about fasting, that impacts cortisol. And cortisol impacts our reproductive hormones.

Women in general have higher levels of cortisol. So it’s really important if we’re fasting for us to manage our cortisol levels. And so intermittent fasting can really disrupt cortisol, which can then impact our female hormones. So that’s, that’s why I’m not for intermittent fasting with women.”

That’s not to say it’s a no-go for every woman. Tamar was sure to add, if you want to try intermittent fasting, talk with your doctor and see if it works for you.

2 – Intuitive Eating Isn’t for Everyone

While I personally have found the concept of intuitive eating to be helpful in tapping into what my body truly wants, I never realized it’s a practice that might not work for some.

“I think intuitive eating can be really beneficial for people who have eating disorders. However, there are aspects of intuitive eating that aren’t accessible to everyone.”

And that group of people, Tamar says, are those managing a medical condition that impacts their appetite or their hormones.

“I like to use the example of insulin resistance, or any sort of hormone imbalance. … If you’re insulin resistant, and you listen to your body, and your body’s telling you you need sugar … you’re going to eat even the sugar.

[So if] we want to practice intuitive eating, it’s really important for us to have stable blood sugar.”

Another group who intuitive eating might now work for? Those who have limited access to healthy food options.

“We are in a food focused environment where we have access to foods in abundance, highly processed, highly palatable foods. … It’s going to take a lot of willpower to not want to indulge in those foods.

“And the reality is that highly processed, energy dense, high sugar foods are inherently addictive. So it’s going to be really hard for you to regulate how much you’re eating.”

3 – Beware the “Cleanses”

By now you’ve seen some celebrity or influencer claim the miracle benefits of “the cleanse.”

Each one is different, but the idea behind them is the same—restrict your calories, and force your body to “cleanse” or “detoxify” itself in the process.

While Tamar says these cleanses can be helpful in one regard, it’s not in reference to your metabolism.

“I think when we talk about kick starting things, it’s not really from a metabolic perspective, it’s more from a motivational perspective. So people are motivated when they do a cleanse, because they see results quickly.

They’ll lose … five pounds in a week, which is a lot. And that will then kickstart their motivation.

But we’re not kickstarting your metabolism, we’re actually doing me the opposite. The research really says that, like the slow and steady weight loss is the weight loss that actually stays off, right.

So losing weight isn’t necessarily the hard part, keeping it off, it’s the hard part. And for constantly doing these extreme diets.

The reality is that in the long term, they’re actually doing a lot of damage to their metabolism.”