11 People Who Should Never Try Intermittent Fasting

Receiving adequate sleep each night is crucial for healing and repairing muscles from exercise, supporting brain function, and even maintaining emotional well-being.

You have sleep problems.

According to the Academy of Nutrition and Dietetics, "Disordered eating is used to describe a range of irregular eating behaviors that may or may not warrant a diagnosis of a specific eating disorder."

You've had a history of disordered eating

As one would likely assume, attempting to do intermittent fasting while engaging in an intense training cycle is not an ideal—or safe—combination. If you're training for a marathon or regularly do CrossFit, you may want to reconsider doing IF.

You're engaging in intensive training

As if digestion issues weren't cumbersome enough to deal with on their own, adding a wonky eating schedule into the mix can only cause more gastrointestinal distress. "If you already have problems with digestion (e.g. IBS), intermittent fasting may worsen your symptoms," Calder says.

You have digestion issues.

Food provides sustenance and energy, and it enables you to focus. When you're extremely hungry, all you can think about is food, which diverts your attention away from immediate tasks at hand.

You work a job that requires intense focus

People who live with diabetes already deal with frequent spikes and drops in blood sugar throughout the day, so the last thing they need is to heighten those blood glucose responses via fasting.

You have diabetes.

Engaging in IF while pregnant or breastfeeding can pose a threat to a child's development. Calder says, "Pregnancy and breastfeeding require adequate intake of calories for proper development of the baby and milk production.

You're pregnant or breastfeeding.

There are some medications that must be taken in the presence of food because without it, they can make you feel nauseated or light-headed, among many other side effects.

You're on medication that must be taken with food.

Those who have recently experienced a major illness or are currently facing one should not engage in IF without clearing it with a doctor first.

You have a weak immune system or cancer.

Your work schedule can greatly influence your ability to engage in IF successfully. For example, if you work the night shift and have to sleep during the day, but one of your eating periods falls within the daytime, what do you do?

Your lifestyle can't accommodate the eating hours.

It takes a lot of mental strength to commit to IF. "It takes a lot of willpower to go for extended periods of time without food," says Calder.

You simply don't want to eat in a designated time frame.