My friend Madelyn sends me periodic requests to address her issue of late-night snacking. She wonders if this habit may hinder her efforts to lose weight.

Indeed it may, say researchers. And they blame it on our circadian rhythm — our “internal clock” that tells us — among other functions — when to sleep and when to wake up.

Seems this circadian control center also regulates our hunger signals, according to a recent study at Oregon Health and Science University. Researchers kept volunteers in a controlled environment and found they were the least hungry in the morning around 8 a.m. And most had a surge of hunger in the evening around 8 p.m. This cycle of hunger might explain why some are prone to skip breakfast and then be driven to overeat at night.

Why are we wired this way? Perhaps our appetite “peaks” at night to feed us before we enter a long period of sleepful fasting, say researchers. And guess what we tend to crave when the lights go dim? Sweet, starchy and salty foods (as in candy and popcorn at the movies).

Whatever the reason, experts now confirm that late-night eating is a good way to gain weight. Case in point: Sumo wrestlers intentionally pack on the pounds by not eating breakfast and loading up on food — lots of food — later in the day.

Alas, if our goal is not to become sumo wrestlers, we might attempt a few strategies to push back from the hunger that urges us to overeat into the evening:

• Go to bed earlier. Our pioneer ancestors went to bed when the sun went down and rose when it came up-a plan apparently preferred by our circadian rhythm. When we resist the urge to stay up late, we resist the urge to munch when the sun goes down. And we prevent the storage of excess calories into fat-something our body does easily when we overeat at night.

• Get enough sleep. Less than about seven hours of sleep a night does more than just make us cranky, Lack of sleep increases our hunger cues and messes with our body’s ability to control blood sugar levels.

• Reset your circadian clock. Can we do that? We do know that we respond to calories (energy from food) differently at different times of the day. As the day wanes, we expend fewer and fewer calories as we wind down for beddy-bye. And this old adage is still true, say experts: Eat breakfast like a king, lunch like a prince and dinner like a pauper.

Best advice if you want to lose weight? Do the opposite of sumo wrestlers. Eat your larger meals earlier in the day. And snack lightly — if at all — into the evening.