Over the years there has been conflicting information on how, why and even if, certain foods or drinks impact the effectiveness of ADHD medications. For example, does a breakfast high in fat make medications less effective? In this post, I will try to clear up some of the confusion surrounding whether what you eat changes how your medication works.
It is recommended that short acting medications, such as Ritalin be taken between 30 and 45 minutes before eating in order for someone to receive the full effect of the medication. The prescribing information for Concerta, however, indicates it can be taken with or without food.
A study released in 2002 compared the effects of Concerta with Adderall after children had eaten a breakfast high in fat. The study, which was completed by McNeil Labs (the manufacturer of Concerta) showed that high-fat breakfasts had no impact on the effectiveness of Concerta but did slow down the absorption of Adderall.
Although Adderall XR prescribing information indicates that this medication can be taken with or without food, certain foods do often impact the absorption, and therefore the effectiveness of amphetamine based medications.
For example, acidic foods decrease the absorption of the medication, reducing the medication’s effect. Acidic foods tend to make urine more acidic, which increases the rate the medication is released from the body, decreasing the effectiveness. Some foods that acidify the urine include:
Dairy Products, such as cheese, milk and butter
Oils, such as canola, corn, olive, safflower, sunflower, sesame
Grains, such as rice, wheat, corn, oats
Nuts such as cashews, peanuts, pecans, walnuts
On the other hand, when the urine is more alkaline, the medication is not eliminated from the body as quickly and therefore increasing the effectiveness of the medication. Some foods that make the urine more alkaline are:
Vegetables, such as asparagus, broccoli, cauliflower, cucumbers, peas, squash
Fruits, such as apples, bananas, cherries, grapes, grapefruit, oranges, lemons, pineapples, berries, tropical fruits, watermelon
Protein foods, such as, eggs, chicken, yogurt, almonds
The National Alliance on Mental Illness (NAMI) states, “The absorption of amphetamine medications can be reduced if strong organic acids are present in the stomach at the time of taking amphetamine medications. The following foods should be avoided for 1 hour before and after taking an amphetamine medication: citrus fruit, citrus juices, sodas/carbonated beverages, lemonade, Gatorade, vitamins/food and food supplements containing vitamin C.” 
The prescribing information for Intuniv indicates it should not be taken with high-fat meals as this can increase the level of medication in the blood.
This medication can be taken with or without foods (other than foods with a high content of fat).
Strattera prescribing information indicates it can be taken with or without food. The effectiveness of the medication can decrease the rate of absorption, therefore decreasing the effectiveness.
Because ADHD medications can cause appetite suppression, some doctors will recommend that the medication be taken about an hour after breakfast, especially if the children are not gaining weight or have been losing weight because of loss of appetite.
 “Adderall”, Update 2008, March, Julie A. Dopheide, Pharm.D., BCPP, National Alliance on Mental Illness
“Adderall XR Medication Guide”, Revised 2007, March, Shire U.S. Inc
“Concerta Prescribing Information”, Revised 2009, Nov, McNeil Pediatrics
“High-Fat Diet May Affect Absorption of Once-Daily ADHD Medications”, 2002, August, Jim Rosack, Psychiatric News, Vol 37, No. 15, Page 19, American Psychiatric Association
“Intuniv Prescribing Information”, 2009, Shire Pharmaceuticals, Shire US, Inc
“Ritalin, Ritalin SR Prescribing Information”, Revised 2009, April, Novartis Pharmaceutical Corporation
“Strattera Medication Guide”, 2009, July 23, Eli Lilly and Company