We’re in the thick of summer, a hot time for most of us; a time of T-shirts, shorts and bathing suits—the less clothes, the better. A time for staying up later, maybe for being outside longer. And all of these behaviors lend themselves to easily practicing the triad of everyday wellness: exercise, nutrition and stress management. The sun goes down later, all the better for an after-work bike ride or walk or game of some kind. So many fresh fruits and vegetables to try, be it from your garden, a farmer’s market or even the corner grocery store. A weekend by the lake or a day trip to the beach is the perfect prescription for shaking off the stress of the work week.QUIZ: Test Your Health and VitalityTogether, exercise, nutrition and stress management are cornerstones for creating a healthy body chemistry. I’ve said this over and over in my columns to date. Well, at the risk of upsetting the apple cart, I no longer believe that everyday wellness is just based on the aforementioned triad. Rather, there is a fourth pillar: a good night’s sleep.Sleep regulates our body clocks, restores our energy and even helps keep us from gaining weight. Earlier this spring, researchers demonstrated that women in particular are susceptible to “reduced dietary restraint” and weight gain as a result of not getting enough sleep*. The study was small, only involving 16 individuals for two weeks (hardly representative of most of us), yet, I find it a provocative idea and one we can all learn from. After all, how many times have you reached for a snack at night when you’re tired? Or binged on a bag of chips when you’re struggling through a sluggish afternoon at work?MORE: Are You Too Sleepy to Enjoy Your Life?You should think of sleep as another tool in your arsenal to help you stay healthy (and to help keep the weight off). Most of us need between six and eight hours of sleep every night. If you’re falling below this, then it may be time to re-evaluate. So go on, stay outside later tonight, run around and get sleepy, enjoy the sunset if you can, maybe while having a picnic … and then get some sleep!