Every year, kids look forward to a lazy summer vacation when they can sleep in and hang out by the pool. But soon enough, it's time to think about sharpening those pencils—and minds. A healthy diet and some specific lifestyle behaviors can help students clear out the cobwebs and prepare for success in the new academic year.

Here are a few ways to get brains and bodies ready to head back to the classroom.

More fruits and veggies

Eating a well-balanced diet full of fresh, colorful produce may be a great way to help children enjoy good health, both now and in adulthood.

A diet low in fat and high in nutritional value has long been advocated by many major U.S. health organizations as a key component to staving off heart disease, type II diabetes, stroke and most other adult-onset chronic diseases. The USDA recommends that a low-fat diet include plenty of foods with high nutritional value, such as vegetables, low-fat dairy products and whole grains.

Produce packs a powerful punch when it comes to vitamins, minerals and other nutrients—including fiber, which helps regulate the bowels and is believed to keep many diseases at bay. The nutrients in fruits and vegetables may help keep all parts of the body running properly, including the brain, and help ensure that children are healthy, alert and ready to learn.

Instead of packing a bag of chips in a child's lunch box, put in a fig, dried plum or a handful of raspberries, which have very high fiber content. If they're getting bored of the same old sandwich, provide a salad with leafy green vegetables like spinach or kale, or some steamed broccoli.

Chalk up on exercise

After school, it can be tempting to settle in front of the TV and veg out. But it’s much better for the body and the mind to spend that time outdoors getting some exercise and vitamin D instead. Regular exercise helps keep you agile and sharp while preventing obesity (so those snazzy back-to-school clothes fit perfectly) and heart disease. Most movement is considered beneficial as long as it is done in moderation and at your skill level. The World Health Organization recommends 30 minutes of moderate activity every day. Playing sports after school is a great way to get to know new classmates, too—and maybe earn a scholarship someday.

Think zinc

Sure, we want our kids to focus in school, but truth is it can be hard to not zone out when Mrs. Drumble is droning on about quadratic equations. The good news is a readily available mineral can help keep kids alert in class instead of staring out the window. Zinc, an important mineral involved of many of the body's processes, is found in red meat, poultry, oysters, beans, whole grains and dairy products.

Zinc also has a Natural Standard evidence grade of B for treating attention deficit hyperactivity disorder (ADHD), meaning there's good scientific evidence supporting its effectiveness for this condition. Preliminary studies found that children with ADHD may have low zinc levels, though more research is needed before further conclusions can be made. It is important to note that ADHD should not be self-treated, so if you're interested in trying supplemental zinc for this condition, discuss it with a pediatrician first.

Added bonus: Zinc boosts the immune system and is believed to have antiviral activity, so it might just keep kids healthy and help them avoid the common colds and flus that tend to circulate on campus.

Up the iodine

The body needs iodine in order to make thyroid hormones, which are necessary for normal brain development and cognition. Chronic iodine deficiency can lead to numerous health problems. In children, prolonged iodine deficiency may cause learning disabilities, a lower intelligence quotient (IQ) and poor motivation to achieve.

There is evidence that iodine supplementation improves perceptual reasoning, information processing, fine motor skills and visual problem solving in iodine-deficient children. For this reason, it is important for pregnant and lactating women, as well as children, to have sufficient iodine intake.

Iodine is found in foods such as eggs, dairy products, seafood and grain products. It has been given a Natural Standard evidence grade of B for improving cognitive function, indicating strong scientific evidence in support of its effectiveness. But it is important to supplement safely, so please check with your healthcare provider before trying amounts greater than commonly found in foods.

Get a good night's sleep

Sleep is the brain's way of refreshing itself from a long day and preparing itself for the next. Parents should encourage an early bedtime for kids and make sure that their bedrooms are cool, comfortable and quiet. Good rest may help keep memory and attention in tiptop shape, since they are vital to a student's academic success.

However, sleep problems do sometimes happen. Adolescents and teens in particular may be stressed, which can lead to difficulties in falling asleep or staying asleep, making for some tired campers in the morning. In these cases, melatonin may help. This hormone is naturally produced in the body and has been given a Natural Standard evidence grade of B for sleep disorders in children.

A melatonin supplement may help them get the Zs they need, but parents should always check with a pediatrician or pharmacist before starting children on any new herbs or supplements.

Adopting a well-balanced, nutritious diet, regular exercise and getting plenty of sleep may be the key to helping kids ensure success this year. Eating right and resting well may help them stay alert and sharpen their memory in class.