Your height is determined by both your genetics as well as environmental effects. Although several factors that determine your height are out of your control, there are a few things you can do to grow to your full potential.
1- Most of your height will be determined by genetics. Height is a polygeneic trait, meaning that it's influenced by several different genes. Having two short parents doesn't necessarily mean you'll be short, just as two tall parents won't make you a towering giant. However, if most of the people on both sides of your family are short, odds are that you'll be short, too. Don't be discouraged, though - the truth is that you can't know how tall you'll be until you reach full physical adulthood in your mid-20s.
Calculate your projected height. Working in inches or centimeters, you can try to predict your height based on the height of your parents. Add up your mom and dad's heights (in inches or cm).
Add 5 inches (13 cm) if you're a boy; subtract 5 inches (13 cm) if you're a girl.
The answer is your predicted height, give or take 4 inches. Note that this isn't an absolute calculation, but it should be pretty close.
2- Avoid growth-stunting factors. There might not be a lot you can do to increase your height, but you can take several steps to make sure your natural height isn't shortened by environmental influences. Drugs and alcohol are both thought to contribute to stunted growth if they're ingested while you're young, and malnutrition can keep you from reaching your full height, as well.
3- Get plenty of sleep. Research suggests that growing teenagers and pre-teens need between 8.5 and 11 hours of sleep every night. This is because your body grows and regenerates tissue while you're at rest. Make your sleeping environment as calm as possible, and try to eliminate loud nosies and unnecessary light. If you have trouble falling asleep, try taking a warm bath or drinking a hot cup of chamomile tea before bed.
4- Eat right. Ensuring that you're getting all the vitamins and minerals your body requires will help you grow to your full height. Take a supplement targeted at your age group with breakfast each morning, and try to incorporate certain foods into your diet. Here are some specific suggestions:
Get plenty of calcium (found in dairy products and green vegetables). Calcium promotes bone growth, and can help prevent osteoporosis.
Get sufficient vitamin D (which can be obtained through eating fish, alfalfa, or mushrooms, or spending more time in the sun). Vitamin D promotes bone and muscle growth in children, and a deficiency has been shown to stunt growth and cause weight gain in teenage girls. If you don't like fish, consider a fish liver oil supplement (Recent research British Scientist says fish oil supplements don’t work!).
Take in lots of protein (from meat, eggs, tofu or legumes). Proteins provide the essential building blocks your body needs in order to grow. At least one (preferably two) of your meals each day should include a protein.
Up your zinc intake (oysters, chocolate, peanuts, eggs, peas, asparagus and supplements). A zinc deficiency can cause stunted growth in children. The best way to make sure you meet your body's daily need is by taking a vitamin or supplement that includes zinc.
Eat on a regular schedule. You should be eating 3 meals a day, with small snacks between breakfast and lunch, and lunch and dinner. Try to schedule these events at roughly the same time each day.
5- Keep your immune system strong. Some childhood illnesses can stunt your growth. Most of them can be avoided by the routine immunizations you may have had as a baby, but stay on the safe side by ingesting plenty of Vitamin C (found in citrus fruits such as oranges, grapefruits, lemons, parsley and green pepper) and getting plenty of rest as soon as you notice that you feel sick.
6- Practice good posture. Rolling your shoulders or hunching over can actually affect the curvature of your growing spine (and not in a good way). Keep your shoulders back, chin high, and hips over your feet. Walk with purpose instead of slouching or slinking, and try to sit up straight when you're in chairs. Even if you're not actually getting taller, good posture will make you look taller.
7- Cultivate confidence. Being taller might be nice, but it can't make up for a general lack of confidence. Try to talk yourself into feeling comfortable in your own skin, and being generally happy with your looks no matter how tall you turn out to be. A positive attitude will more than make up for any lacking height.
8- Visit a medical professional. If you're from a tall family and you're not growing by your mid-teens, or if your height hasn't changed much from before puberty to during puberty, then it's a good idea to see a doctor. Conditions that can stunt your growth (such as human growth hormone deficiency or autoimmune diseases) are fairly rare, but they do exist. If you're eating a healthy diet and getting plenty of rest but you're still not growing, then it's time to consult a doctor.
Consider seeing a doctor if you're a short adult. Though there are several childhood conditions (such as rickets) that can result in a short height as an adult, you should still ask a doctor about it. There may be ways to make sure that your bones and organs are healthy even though you didn't grow to full height.