Why do late-night snack cravings hit so hard? It’s more than just willpower—circadian rhythms, sleep, and modern habits all play a role. Here’s how to manage them.
Why do late-night snack cravings hit so hard? It’s more than just willpower—circadian rhythms, sleep, and modern habits all play a role. Here’s how to manage them.
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Ever wonder why you can resist snacks all day but then suddenly crave chips or ice cream at 9 PM? It turns out there's a reason for that—and it’s not just a failure of willpower. Your body’s natural rhythms, brain chemistry, and even your sleep habits all play a role in those late-night cravings. Today, we’re going to take a look at the science behind night-time snack urges and what you can do about it.
Welcome back to the Nutrition Diva podcast, where we explore the science behind healthy eating and help you make choices that work for your life. I'm your host, Monica Reinagel, and today we're tackling a challenge that many of us are familiar with. You make good choices all day long but come evening, you feel like you need a salty, crunchy snack, or something sweet. And your self-control is nowhere to be found.
But science suggests there’s a lot more at play here than just a failure of willpower. Our appetite actually follows a circadian rhythm, fluctuating throughout the day and tending to peak in the evening. But our metabolic and digestive processes have their own circadian rhythms. And when we eat at night, we are likely to store more of those calories as fat than if we ate the same number of calories earlier in the day. In other words, our urge to snack peaks right at the time of day that we can probably least afford to.
I know this seems terribly unfair and perhaps even like a design flaw. But let’s look at this in evolutionary terms. As I said, our natural hunger levels tend to peak in the evening and are lowest in the morning, regardless of when we actually eat our meals. And this might have been an advantage in early human history. Most hunting, food gathering, and other work required to ensure survival happened during the daylight hours. Eating and digesting may have largely been reserved for the less productive evening hours, followed by an overnight fast that may well have extended until the following evening.
So a strong evening appetite may have ensured that early humans consumed enough calories to power them through the following day’s work. We modern humans may still feel that increased urge to eat in the evenings. But unlike our ancestors, we also eat all day long–and don’t expend nearly as many calories procuring our next meal!
But, there’s more going on here than just circadian rhythms and evolutionary biology. Recent research suggests that more modern factors such as irregular meal timing, artificial light exposure, and staying up late can intensify this evening hunger surge.
Artificial light exposure at night—especially blue light from screens—can delay the production of melatonin, the hormone that signals to our bodies that it’s time to wind down.
And obviously, the longer you stay awake, the more hours you have to snack. In fact, studies show that simply going to bed earlier can help people reduce the amount of excess calories they consume and promote weight loss.
But getting more sleep is not just about preventing those calories of opportunity. When we don’t get enough sleep, it can disrupt two key hormones that regulate hunger. Ghrelin levels go up, making us feel hungrier, while leptin levels drop, meaning we don’t feel as satisfied after eating.
Not to pile on here, but sleep deprivation doesn’t just make us hungrier—it also influences what we crave. People who are sleep-deprived tend to eat more high-carb, high-fat, and sugary foods. That’s because lack of sleep appears to increase activity in the brain’s reward centers, making these foods seem even more tempting than usual. At the same time, there is reduced activity in the areas responsible for complex decision-making, which are those areas of your brain that you’d need to count on to override such impulses.
OK so that’s a lot of factors stacked up against us in our fight to control evening snacking. But understanding these factors also gives us some insight into how we can best push back.
Our biological urges--including those that cause our appetite to peak in the evening--are the product of eons of evolutionary forces. We're not going to rewire these over the weekend! And, although some have attempted it, re-creating the lifestyle of our primitive ancestors--whether by eating only once a day, or eschewing all artificial light, or running after wild game with crossbows, or whatever--may not be realistic for you.
But if you are struggling to control night-time snacking, it’s worth at least considering whether your sleep habits could be playing a role. Small changes—such as limiting blue light exposure in the evening—may help improve sleep quality and regulate appetite. And simply getting to bed earlier could eliminate hours of potential snacking while also improving metabolic health.
Secondly, make sure your daytime meals and snacks are both sufficient and satisfying. Under-eating can set you up for rebound hunger later on. And meals that are higher in protein and fiber can make you feel more satiated. But I think it's also important that your meals be satisfying in terms of flavor. Even if you are covering your nutritional needs, if you are not truly enjoying your meals, you may be more susceptible to those extra-curricular urges. And part of this strategy may be purposely planning a little treat to enjoy in the evening. So that instead of just trying to resist the urge to snack, you can redirect it in a healthier direction.
But there's one other possibility here. If appetite is highest in the evening, some might argue that it makes sense to structure eating around this natural rhythm rather than fighting it. This may not be ideal in terms of maximizing our calorie burning and minimizing our fat storage. But it might be better than eating the majority of your (planned) calories early in the day, because this is what aligns with the science, and then eating a bunch of unplanned calories late in the day, when your body and brain would prefer to eat.
You could, instead, decide to plan around that preference--eating lighter earlier in the day and eating the majority of your (planned) calories in the evening. In the long run, this might result in eating a more appropriate number of calories over the course of the day.
I'm not saying that this would be the best solution for everyone. Some people might find that eating earlier in the day and holding the line on evening snacking, even if that is sometimes challenging, ultimately helps them feel and function better. This is definitely something that you can experiment with and see what strategy delivers the best overall results for you in terms of your energy, appetite, enjoyment, and weight management goals.
The main point I want to make today is that our tendency to crave snacks in the evening isn’t just our brains behaving badly. It’s partly driven by biology, but also influenced by modern behaviors and amplified by factors like sleep deprivation and artificial light exposure.
But when we understand these influences, we can make informed choices. Maybe that means prioritizing sleep and reducing blue light exposure in the evening to help regulate hunger hormones. Maybe it means ensuring that our meals throughout the day are satisfying—both in terms of nutrients and enjoyment—so we’re not set up for rebound cravings at night. And for some, it might mean experimenting with meal timing.
There’s no one-size-fits-all solution, but by paying attention to your own patterns and experimenting with different approaches, you can find what works best for you. So, if late-night snacking is something you struggle with, try one or more of the strategies we discussed today and see how it impacts your hunger, energy, and overall well-being. And as always, I’d love to hear what works for you!
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Nutrition Diva is a Quick and Dirty Tips podcast. Our team includes Brannan Goetschius, Nathan Semes, Davina Tomlin, Holly Hutchings, Morgan Christianson.and Nathaniel Hoopes.
That's all for this episode. Thanks for listening! I'll see you next week.