Summarize the following:
Your hair is composed mostly of protein, so having lots of protein in your diet is essential for healthy hair. If you're not getting enough, your body can shut down the supply of protein to your hair and use it for the most essential of many other body functions.  When your hair doesn't get enough protein, it shuts down growth. As a result, when existing hair reaches the end of its cycle and naturally falls out (in a process known as catagen) it can seem as if you have less hair than normal. Don't worry though - once you commit to getting enough protein in your diet, your hair will start to grow again and feel thicker in no time. The best sources of protein include fish (like tuna, salmon, and halibut), white poultry (such as turkey and chicken), eggs, dairy products (including milk, cheese, and yogurt), beans (like kidney, white, lima, baby lima, and black beans) and beef, veal, pork, and tofu. B vitamins are necessary for healthy hair growth, so if you're not getting enough of them as part of your diet, your hair could be affected. On the other hand, excess vitamin A can trigger hair loss, so you may need to cut back.  Having low levels of B vitamins in your diet is pretty uncommon, especially in the U.S., but it can be an issue for some people. To naturally increase your intake of B vitamins, eat more fish and lean meat as well as starchy vegetables and non-citrus fruits. To decrease your intake of vitamin A, try to cut back on any supplements or medications containing vitamin A. Keep in mind that the recommended daily intake of vitamin A (for anyone above the age of four) is 5,000 IU. Low-calorie diets often deprive your body of many of the vitamins, nutrients, and healthy fats it needs to function properly and maintain healthy hair growth.  In addition, rapid weight loss (as the result of following a low-calorie diet) can cause major physical stress to the body, which may trigger hair loss. It is important to supply your body with all the fuel it needs. If you're trying to lose weight, you should do so by making healthier, more nutritious choices and by exercising regularly. Aim to lose weight slowly and steadily, rather than trying to do so all at once using starvation tactics. A safe, manageable goal is to lose one to two pounds per week. Many high-fat, high-calorie foods are actually very good for you, provided you make the right choices. Things like nuts, avocados, and oily fish are all high in monounsaturated fat, but they are also very healthy and should be eaten as part of a balanced diet. Taking good care of your hair will contribute to its overall health, making it stronger and less prone to fall out.  Start by using a shampoo and conditioner suited to your hair type. Dry hair will need richer, super-moisturizing products, while oily or very fine hair will require lighter products designed for regular use. Try to avoid using hair products with too many chemicals in them. Shampoos containing sulfates or parabens should be avoided and more natural, organic ingredients should be used. Also avoid washing your hair too often, as this can strip hair of natural oils, causing it become dry, brittle and prone to breaking. Every two to three days is a good schedule for most hair types. Nourish your hair even further by getting moisture and shine treatments at your local salon, or by making natural hair masks at home. Oils such as coconut, argan, and almond can improve the condition of hair dramatically, making it soft and silky. Keep your hair in good condition by getting it trimmed every six to eight weeks. This eliminates split ends and helps your hair to look and feel great. Overstyling is one of the biggest issues when it comes to healthy hair. Nowadays, many women are obsessed with blow-drying, straightening, and curling their hair using heated styling tools. These wreak havoc on the condition of hair.  Try to minimize the use of styling tools. Experiment with naturally air drying your hair, scrunching your hair using a little hair mousse, or curling your hair using no-heat methods, such as hair rollers. You should avoid playing with your hair too much, i.e., twisting, pulling, or breaking off split ends. You should also be careful with ponytails - tying them too tightly can cause hair to fall out (traction alopecia). Wear your hair loose as often as possible (especially at night) and experiment with loose, low ponytails and braids. Don't brush your hair too often either. Be careful when using color treatments on the hair, as they can quickly dry, damage, and over-process your hair. Wait as long as possible between dye jobs, and think long and hard before you decide to go down a color route which involves bleach. Consider using more natural hair coloring techniques, such as henna, which nourishes as it colors.

Summary:
Eat enough protein. Increase B vitamins and decrease A vitamins. Avoid low-calorie diets. Take good care of your hair. Avoid over-styling your hair.