Curious how sleep and your weight are connected and why? Research shows there are two main drivers for why poor sleep makes it harder to lose weight: Behavioral and biological. We can’t say from the research that there is a causal relationship for them but there is definitely enough evidence to say poor sleep hygiene and weight gain are interrelated.

As the seasons change, outside temperatures begin to drop and we have less daylight, our sleep rhythms begin to change, but our schedules do not. Think about why daylight savings time makes everyone irritable. Hint: it's not just the hour lost! It’s because your balance was thrown off. Sleep is very multidimensional and is interrelated with all the different Target100 program pillars.

Here are some behaviors that, as a result of poor sleep, can make weight loss harder ...

• Overeating due to more time awake.


• Less desire to exercise or decreased quality of exercise due to increased fatigue.


• Eating at night because of gaps between meals causing cravings for sweet and salty food. Cravings for simple sugars and high-fructose corn syrup exacerbate hormonal imbalance.


• Not eating breakfast due to lack of time in the morning leading to overeating for successive meals.


• Less self control over cravings.

5 habit shifts to lessen decision fatigue when we're sleep deprived.

#1 Meal prep for breakfast with quick to go items like high quality bars, overnight oats, and boiled eggs.

#2 On days with particularly less sleep, avoid high intensity workouts and turn to light cardio or yoga.

#3 Hide snack foods away in a hard to access location to mitigate cravings and avoid the kitchen in the evening.

#4 Create a restful sleeping environment absent of food, televisions, and other electronics.

#5 Try to resolve your worries or concerns before bedtime. Learn to leave tomorrow's problems for tomorrow. Stress has a negative feedback loop with sleep ruining your rest and in turn ruining your sleep.

The hormone connection

Stress and fatigue associated with poor sleep is related to dysregulation of the hormones, ghrelin and leptin, leading to increased appetite and diminished feelings of fullness. Ghrelin is responsible for telling our brain that our stomachs are empty and stimulates our desire to eat. Leptin is a hormone that suppresses our appetites when we no longer need calories and is directly related to how much body fat we have. With high ghrelin and low leptin from insufficient sleep our bodies cannot help but keep weight on.  Poor sleep also increases cortisol, which plays a role in accumulation of fat as a result of decreased metabolism. From an evolutionary perspective, cortisol was useful as it helped us retain weight and fat when in stressful situations to help us survive. Nowadays we just get extra hungry from stress-induced high cortisol but we don't really need the extra energy stores. Sleep scientifically impacts your ability to make decisions about how to fuel your body to support your weight loss and wellness goals.

As a result of these hormonal changes, weight loss research has shown that losing sleep while dieting can reduce the amount of weight lost and encourage overeating. Poor sleep increases inflammation, which contributes to insulin resistance (a decrease in the effectiveness of insulin) and elevates blood sugar. Insulin resistance makes weight loss more difficult because the body stores excess blood sugar as fat.

Get back on your sleep routine quickly

It’s okay to stay out a night or two but it's important to get back on to a healthy sleep routine as quickly as possible. Yo-yoing sleep routines, just like yo-yo diets, are not sustainable and end up doing more harm than good in the long term. The first step toward building a more consistent sleep routine is to build awareness of how sleep affects you personally. Being curious and reflective of your own needs around sleep will help you mitigate the effects that it has on your other Target100 program pillars including stress, exercise, and movement. You can use a sleep tracker (like the one you get when you sign up for the Beginners Course!) to learn how much sleep you need, the quality of rest you get, and what affects your sleep. From there you can begin to improve your routine and improve the duration and quality of your sleep at night.

All this science may not be that useful to know in detail but knowing the effects and creation of poor associated habits that come with bad sleep is key in staying healthy and losing weight. So be observant and intentional when going to bed and waking up! Check out these 5 ways to improve your sleep so you can really unlock this powerful pillar and see how it can support you in your weight loss journey.

This blog post was written by our amazing dietetic intern Jerahmeel Fong.