Can Calorie Deficit Cause Sleep Problems?

It is well known that calorie deficit creates a host of metabolic adaptations like lowering resting metabolic rate and energy expenditure. But what about sleep quality?

Can calorie deficit cause sleep problems?

As a general rule, a long-term calorie deficit can cause sleep problems. Long-term dieting, lifestyle changes, and mealtime schedule modifications can interfere with the circadian rhythms and impact sleep. Also, food composition can influence sleep duration and quality.

However, short-term calorie deficit has a positive impact on sleep. As long as you do it right. In this article I will cover

  • Can Dieting Affect Sleep?
  • Can a Low-Carb Diet Cause Sleep Problems?
  • What Foods Cause Insomnia?
  • Can Calorie Deficit Cause Insomnia?
  • Can Not Eating Enough Keep You Awake?
  • Can Lack of Sleep Cause Weight Gain?

Can Dieting Affect Sleep?

In general, dieting can affect sleep. Prolonged calorie deficit makes changes in the sleep/wake pattern and sleep duration by influencing melatonin secretion, and circadian rhythms. However, periodically repeated short-term calorie restriction improves serotonin and sleep patterns.

It’s all about dose-response. Just like when you exercise or take antibiotics. 20 minutes of a workout can be like therapy, and make you feel like a new person. Or when you take a low dose of doxycycline when you have acne.

But what happens when you go over the board? When you take 10 times more than you should, or you gym for 5 hours every day?

Benefits are gone.

Same with a calorie deficit. Just because calorie restriction is good, more doesn’t mean better. It’s about small and often. Slow and steady wins the race.

Calorie Deficit and Serotonin

Serotonin is a well-known happiness hormone. It plays a role in many mood-related actions.

But apart from making us feel like on cloud 9, serotonin is also modulating our circadian rhythm, sleep, and walking patterns.

Short-term calorie deficit seems to positively impact our serotonin, mood, anxiety, memory, and quality of life in general (source). On the other hand, thank circadian plasticity, the more you stay in a calorie deficit, the more you will lower the serotonin levels, increase your stress hormones and lower a chance for a good night’s sleep.

The secret sauce is in the dose. Having a medium to light calorie deficit can help you stay in a negative energy balance for a long time, without mood swings and sleep problems.

Calorie Deficit and Melatonin

Melatonin is a neurohormone secreted mainly at night time. It is responsible to regulate circadian rhythms and help us to fall and stay asleep. It’s a top player in a sleep-wake cycle.

Melatonin is made of amino acid tryptophan. Which means that diet rich in protein will have a positive effect on the production of this sleep improving hormone.

Calorie deficit and intermittent fasting do have an impact on melatonin secretion levels. Studies show that very low-calorie intake (<300 kcal per day) from 2 to 7 days reduces melatonin levels in the blood by about 20% (source).

HOT TIP: Adding a small amount of glucose (simple sugar) during short-term fasting (calorie deficit) returns the melatonin to normal levels.

It shows that for optimum function of melatonin certain minimal amount of glucose is required. This means by having a small fruit handy, somewhere in the evening time can be just what you need to sleep better (source).

You see, that one of the reasons why low-carb diets can cause sleep problems.

Can a Low-Carb Diet Cause Sleep Problems?

In general, a low-carb diet can cause sleep problems. Food has a strong influence on melatonin synthesis, and foods that are low in carbohydrates lower melatonin levels and increase cortisol levels, which can contribute to sleep quality and duration.

On the other side, people who follow Mediterranean diet experience lower difficulty with initiating sleep, maintaining sleep, and early morning awakening (source).

This means sleep quality is related not as much to calorie restriction, but to the specific nutrient intake. Lower food variety and adhering to a special diet (low-carb, keto) for an extended period of time contribute to lower melatonin and poor sleep.

HOT TIP: You can stay in a calorie deficit and enjoy a restful night’s sleep, as long as you have a variety of foods in your diet.

A lot of plants contain melatonin, or it’s precursor tryptophan.

Foods High in Melatonin

There are several foods that are high in melatonin.

  • Tomato 3–114 ng/g
  • Walnuts 3–4 ng/g
  • Cereals (rice, barley) 300–1,000 pg/g
  • Strawberry 1–11 ng/g
  • Olive oil 53–119 pg/ml
  • Wine 50–230 pg/ml
  • Beer 52–170 pg/ml

Apart from that, foods that are rich in nutrients like calcium, potassium and magnesium are associated with improved sleep.

What Foods Cause Insomnia?

There are not any specific foods that can cause insomnia. It is more of a micronutrient deficiencies issue, rather than specific food items. Some of the deficiencies include:

  • Tryptophan
  • Vitamin B1
  • Folate
  • Phosphorus
  • Magnesium

Those nutrients seem to play a role in a good night’s sleep. This specific information is based on the national examination survey (source).

The problem with examination survey studies is that they are done by filling up the questionnaire. You answer 10-20 questions about what you normally eat. That’s it.

And based on their “diet” they look at what nutrients are people missing in their diet and link that with insomnia complaint.


Here are some other nutrients and stimulants that are well-documented that can cause insomnia.

  • Excessive caffeine (>500 mg per day)
  • Sugar
  • Green tea
  • Alcohol

Also, overeating behaviors and wake-promoting neurochemicals like noradrenaline, acetylcholine, histamine, and orexin can lead to insomnia and sleep problems.

Can Calorie Deficit Cause Insomnia?

The calorie deficit cannot cause insomnia. Insomnia is a sleep disorder that is typically caused by stress, shift work, traveling, jet lag, irregular sleeping habits, or eating too much at night. Dieting and calorie restriction can temporarily affect circadian rhythms, but cannot cause insomnia.

Long-term fasting lowers melatonin levels and increases your cortisol (stress hormone), which can cause some sleep disturbance.

So if you’re currently on a calorie deficit and having a problem with sleeping, start by moving up your mealtime.

I used to have this problem when I was doing one meal a day. I was starting my day with a big meal. And then I wasn’t eating anything till the next morning.

The problem was with sleeping.

I couldn’t sleep. And only when I’ve move up my meal, not only I had more energy in the morning, but also I could plug-in a workout and be more productive.

HOT TIP: Take a spoonful of unrefined coconut oil first thing in the morning to combat the carvings. This way you can move up your meal later on during the day.

Can Not Eating Enough Keep You Awake?

Not eating enough can keep you awake. Sleep is regulated by melatonin. Energy restriction reduces the nocturnal secretion and synthesis of melatonin. Therefore, eating not enough calories for too long, or practicing extended versions of intermittent fasting, can change the circadian rhythms.

There are ways to minimize this problem by adding supplementation of melatonin. However, this will only cover the symptom, not the cause.

It is much better to have a small snack at night and not rely excessively on supplements.

I used to make a big mistake when trying to lose weight by using so many supplements, and not finding out the actual causes of the problem.

I was an idiot.

I would drink a protein shake 4-6 times a day as a meal replacement. Did it help? Nope.

Why I Can’t Sleep When Cutting Calories?

Not being able to sleep when cutting calories may be due to low-calorie intake. When cutting, lowering your calories by 250-500 calories, or even eating at your basal metabolic rate. This is enough to cause calorie deficit, without going too low and have sleep problems.

Calorie deficit doesn’t have to mean all or nothing.

It means you can literally reduce your calorie intake by few calories, or even by reducing one meal. That’s it

Of course, everyone wants fast results. But this is a process.

Just like your hair needs time to grow.

The same with weight loss and calorie deficit.

But when you have compromised sleep, all the effort goes out of the window.

Can Lack Of Sleep Cause Weight Gain?

Lack of sleep can cause weight gain. Sleep restriction and sleep deprivation can have negative changes in body weight, body composition, and metabolic variables. Lack of sufficient sleep may lead to increase blood glucose levels, insulin levels and compromise weight loss results.

This is like taking one step forward, and two step back. Not only you’re not moving, but you’re getting worse than you’ve been before.

There is a massive link between short sleep duration and higher total energy intake. You eat more when you’re not well-rested. And obviously, you never overeat on fruits or veggies.

It’s always the greasy food that you crave when your sleep was bad. Over time that can add to weight gain, mess up appetite-related hormones leptin and ghrelin, which then start to impact your sleep patterns.

It’s like a vicious cycle.


Changing your diet, and going too much on calorie deficit can slowly affect your sleep quality. And once the sleep is gone now the eating starts, without the brakes.

The best way to stay out of trouble is to change the foods you eat and eat closer towards the late afternoon. This will help you maintain your melatonin levels. And if you still struggle, have a couple of fruits and you good to go.

Michal Sieroslawski

Michal is a personal trainer and writer at Millennial Hawk. He holds a MSc in Sports and Exercise Science from the University of Central Lancashire. He is an exercise physiologist who enjoys learning about the latest trends in exercise and sports nutrition. Besides his passion for health and fitness, he loves cycling, exploring new hiking trails, and coaching youth soccer teams on weekends.

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