Is cortisol sabotaging your weight loss efforts? Experts sound off

Stock image of woman standing on scales
Like most things that affect health, it is more complicated than controlling one hormone. Photo credit: Getty Images

You might believe cortisol is the culprit sabotaging your fitness and weight loss efforts if you're getting your guidance from social media.

And if you could just get your cortisol levels to where they need to be, everything else will fall into place - right?

Like most things that affect health, it is more complicated than controlling one hormone, said Britni Vincent, a registered and licensed dietitian in St Paul, Minnesota.

Cortisol may have some influence over how bodies retain weight, produce insulin and what kinds of foods we crave, but it is one of many factors that influence weight, said Dr Charlotte Hodges, chair of the surgery department at White Rock Medical Center in Dallas.

Factors such as environment, behaviour, gut bacteria and genes also play huge roles, she added.

But cortisol is an important hormone that affects many things in the body, and it might be time to get to know it better.

What is cortisol?

Cortisol is the body's primary stress hormone, according to the Mayo Clinic. It increases blood sugar, enhances the brain's use of glucose and makes more tissue-repairing substances available while curbing functions that would hurt in a fight-or-flight situation.

"It kind of allows your body to utilise energy quickly in stressful situations," Hodges said. "If I'm operating, and I encounter something, there are lots of different processes in the body that are affected (by cortisol). I can kind of get more mentally acute and much more awake."

The hormone is essential to our daily functioning, Vincent said. It has an inverse relationship with melatonin, kick-starts our day and then lowers at night to allow us to rest, she added.

Cortisol has an optimal biorhythm to help us maintain our daily activities and respond to stress, but problems arise when we get too much or little of it, or the wrong levels at the wrong time, Vincent said.

"Overproduction of cortisol can cause belly fat," Vincent said. "As your cortisol goes up, so does your blood sugar. And when our blood sugar goes up, our pancreas is going to output insulin."

Cortisol itself can cause weight gain, but then the increased insulin can add to weight gain as well, she added. On top of that, high stress and greater production of cortisol can lead to a breakdown in your muscles, Vincent said.

How do we know when levels are off?

There are lab tests to determine if cortisol levels are where they should be, but they are usually only given to people who have a condition affecting cortisol levels, Vincent said.

An increase in most people's cortisol levels "wouldn't be something so dramatic where they would have to go seek an endocrinologist to go get treated," Hodges said, adding that it is still a good idea to get annual checkups with a primary care doctor.

While most people don't need to keep a close eye on their exact cortisol levels, they should be aware their behaviour can have an impact, Vincent added.

Some are obvious psychological stressors around work, relationships and difficult events, Vincent said. But some daily activities can also affect our cortisol levels.

These include eating too much sugar or processed carbohydrates, not getting enough sleep or consuming too much caffeine, Vincent said.

"Our body doesn't necessarily discern stress from eating sugar versus a deadline at work," Vincent said. "Our body's going to respond in the same way."

Is your workout messing with your cortisol?

Some recent posts by fitness influencers on social media have promoted avoiding high-intensity workouts to keep cortisol low, but Vincent and Hodges don't see any definitive evidence to support that.

High-intensity exercises or endurance workouts may exacerbate high cortisol levels if someone is not sleeping well, suffering from stress or eating a lot of sugar, but people who are managing stress won't necessarily respond the same way, Vincent said.

And if someone is looking to incorporate more exercise, the best workouts are the ones that keep them going, Hodges said.

"I don't think you doing high-intensity workouts is going to negatively impact your cortisol," she added. "If that's what's going to get you out to go and exercise, more power to you."

But if you haven't been as active, a walk outside might be the best way to start, Hodges said.

"The best thing that people can do is literally go outside and go for a walk, even if it's just for 10 minutes," she said. "Low and slow is a better way. And that will also give you some time for yourself to think through your day if you're really stressed."

How to get your cortisol levels where they should be

If cortisol is something you should be aware of but don't necessarily need to monitor too closely, what can you do to optimise your levels?

"I really recommend to my clients focusing on the stressors that you have control over," Vincent said.

Ensure you are getting at least 7.5 hours of sleep - and doing your best to make that good quality sleep, she added.

For better sleep, experts recommend sticking to a consistent sleep schedule, creating a wind-down routine, turning off computer screens and other devices early before bedtime and keeping your bedroom cool and dark.

"We're talking about not just quality and quantity of sleep, but regularity, getting the same good sleep night after night," sleep specialist Dr Raj Dasgupta, an associate professor of clinical medicine at the University of Southern California's Keck School of Medicine, told CNN earlier.

Vincent also recommends focusing on eating whole, real foods and limiting processed foods and sugars.

"Clinically, I find when people are eating more of a whole, real food diet, they have less anxiety, their sleep is better, they have more energy," she added. "Generally, they're happier, so they're able to handle those other stressors a lot better."

Taking time for your mental health is also helpful, Hodges said. She recommends journaling, mediating, praying or taking a walk in nature. Taking time to tend to mental health often can be overlooked, she said.

"People schedule themselves 30 to 40 minutes to go get their nails done, but will they give themselves 10 minutes just to go for a walk?" Hodges asked.