There are a number of diets or dietary interventions that have proven helpful for ASD children. Often, these diets restrict certain components of food. For example, the Specific Carbohydrate Diet (SCD) restricts the types of carbohydrates a child may eat. The gluten-free, casein-free diet (GFCF) does not allow for the proteins found in many grains (wheat, rye, etc) and dairy.

There are many other options for diet; however, the main focus of any good diet should be to remove substances that may be detrimental and to increase healthful, nutritious foods that can help the body heal and grow. Perhaps the best book to provide information about each of the popular diets is Julie Matthew's Nourishing Hope. This book is also a good resource for information on cleaning up the home environment.

While informing yourself of dietary options and making the decision as to which one(s) might be best for your child and your family situation (see Interventions for complete information on dietary intervention choices), you can take the following dietary steps, which will be beneficial for anyone, regardless of individual needs:

•Reduce the amount of sugar in the diet. It feeds bad bacteria and yeast which in turn have been associated with negative behaviours such as aggression, hyperactivity, poor sleep patterns, soiling, and smearing. Often reducing sugar means replacing foods entirely. Many prepared foods are filled with "invisible" sugar. Learn to read labels carefully if you buy prepared foods, and look for some of the more common names that mean sugar: corn syrup, glucose, maltose, fructose, fruit juice concentrate, dehydrated cane juice, dextrose or dextrin, or anything with syrup as a part of the ingredient. If you make your own food, you can control amounts of sugar much easier. Often people will reduce sugar amounts, replace white sugar with raw honey, and add spices such as cinnamon to provide more flavour.

•Remove aspartame (NutraSweet, Equal). Aspartame is a neurotoxin and a common suspected cause of hyperactivity, aggression, and impulsive behaviour. It is important to note that many prepared products that boast of low sugar may contain aspartame.

•Remove MSG (Monosodium Glutamate). MSG is an excitotoxin which is also a suspected common cause of hyperactivity. See www.msgtruth.org/avoid.htm for a list of foods that commonly contain MSG.

•Reduce and aim to remove all artificial colours, flavours, and preservatives. "Artificials" like these are not nutritious, and are a common suspected cause of negative behaviours, attention deficit, and hyperactivity.

•Remove fluoride toothpaste and replace with a non-fluoride, SLS-free (Sodium Lauryl Sulphate) toothpaste. Fluoride is a suspected neurotoxin and SLS is a caustic detergent.

•Buy organic where you can. Buying organic can be costly but recent studies have highlighted the positive impact on children an organic diet makes; one such study can be found here www.ehponline.org/docs/2005/8418/abstract.html Information provided by the American-based Environmental Working Group about buying organic www.foodnews.org/index.php can help you make informed decisions about the fruits and vegetables that are most important to buy organic. Washing fruit and vegetables well can help, as can peeling (you will lose important nutrition though); however, it is best to buy organic as much as possible. In the UK, there are a number of excellent organic farmers who will often deliver products such as meat, fruit, vegetables, and dairy right to your door at very reasonable prices.

•Remove all trans fats and hydrogenated fats. Trans fatty acids, or trans fats as they are more commonly known, have been much in the news lately, and are now commonly accepted as very detrimental to health. In particular, trans fatty acids fill the omega fatty acid receptors in the brain, starving our children's brains and possibly causing damage in the long term. Trans fats include hydrogenated oils, partially hydrogenated oils, margarine, industrial deep fried foods, and very often peanut butter (not the natural peanut butter) and mayonnaise.