It can be easy to justify losing sleep when you have an especially busy week, or if you have a crucial project that comes up at the last minute. However, sacrificing your sleep can lead to several health issues, including slowing down your weight loss and even causing you to gain more weight.

Losing even 30 minutes of sleep compared to what your body needs can make weight gain more likely. When you’re not getting enough sleep, your body automatically switches into survival mode, which can cause your metabolism to slow down.

There are some significant physical changes that occur when you are sleep-deprived. Here are a few that have the most impact on whether you lose or gain weight.

Change at the hormonal level

Two important hormones help you determine when to eat and when to stop eating. Ghrelin signals hunger, and leptin lets you know when you should stop eating.

When you aren’t getting enough sleep, ghrelin levels increase, and you feel hungrier more often. In addition to that, leptin levels decrease when you’re sleep-deprived—that means your body isn’t giving you reliable satiety cues to know when you should finish eating.

If you find that your dietary self-control is out of whack when you’re not sleeping well, it’s not just your imagination! To make matters worse, levels of cortisol (the stress hormone) understandably increase when you’re sleep-deprived, and that can also push you to make less-healthy food choices than you typically do.

Increased risk of weight gain, insulin resistance, and diabetes

There is also research that indicates sleep deprivation can be a risk factor for weight gain, insulin resistance, and even type 2 diabetes.

This effect builds up over time, but studies show that insulin resistance is affected immediately when you lose sleep. According to a recent study presented at the Endocrine Society’s national meeting, even losing 30 minutes of sleep each weekday may increase your risk of obesity and diabetes.

Michael Breus, PhD, a sleep specialist, notes that “when you’re stressed, your body tries to produce serotonin to calm you down. The easiest way to do that is by eating high-fat, high-carb foods that produce a neurochemical reaction.”

Getting too little sleep can have serious negative effects for your weight loss goals and your health in general.

What can you do?

Many people find it difficult to fall asleep and stay asleep, and it’s often a challenge to find the time you need to sleep. Adults need between 7 and 9 hours each night, but the exact amount is different for each person.
Always changing the times you go to bed and wake up? That can put you at a higher risk for increased body fat and elevated insulin levels. Avoid that risk by setting a consistent bedtime and waking up at the same time, even on weekends.

Avoid using your bed for working or watching TV. Ideally, your bed should be for sleep and sex and nothing else. Minimize light from TVs, laptops, and your cellphone before you go to bed, as that light can trigger wakefulness.

You should also keep an eye out for any issues that might keep you from getting a restful night sleep. That can include food sensitivities, fibromyalgia, menopause, chronic fatigue syndrome, thyroid issues, stress, depression, and heavy metal toxicity. If you think one of these issues is keeping you from getting the sleep you need, it’s a good idea to talk with a medical professional you trust.

It can be a challenge to get enough sleep, but sleeping well is important to achieving your weight loss goals, and it can improve your general health in other ways as well.