When we think of weight loss or muscle growth, we often think that exercise and nutrition are the cornerstones to achieving the new physic we want and sleep rarely comes to the front of our minds. But sleep plays an important role, if not the most important, when we know how much sleep affects hunger and energy.

It is recommended that we get between 7 to 9 hours of sleep a night. Now this will change from person to person as we are all different, however, if we are not hitting the amount of sleep we need it can take a toll. A study conducted by Li, 2021 found that sleep duration under 7 hours is associated with the occurrence of people who are overweight.

Our appetite hormones, leptin and ghrelin, may be influenced by our sleeping habits. Leptin helps to prevent our hunger response (in other words, helps keep us feeling full) and ghrelin is known as the “hunger hormone” as it plays a short-term role in appetite control and lets us know when it is time to eat. A study by Taheri et al (2004) concluded that “Participants with short sleep had reduced leptin and elevated ghrelin.” In other words, this outcome is more likely to increase a person's appetite and therefore it could be more difficult for someone to stick to an energy-controlled diet.

Along with a change in our appetite, a lack of sleep can also impact the food choices we make to fuel our bodies. Foods high in sugar and fast energy-delivering carbohydrates sound incredibly appealing after a lack of sleep, but why is that? Sleep deprivation can increase reactivity in our brain's reward system and when that happens a healthy chicken salad won't do the trick when we can reach for a salty bag of crisps to satisfy our hunger for a short time.

When we are sleep-deprived it can be hard to find the motivation to go to the gym. When we are running on 5 cups of coffee just to make it to the end of the working day, how can we possibly muster up the energy to hit the gym for a heavy resistance session or cardio? Ultimately, many of us give up the idea and head home to try to make the promise of “I’ll go tomorrow.”

In short, sleep has a massive effect on us. It can change how we view what foods we want to eat, and how hungry and satisfied we are after a meal which can then make it more likely for us to eat more energy than we need. Motivation can slip and we can skip those challenging sessions that help up get closer to our goals.