First, I should explain that the anti-inflammatory diet is designed primarily to reduce the risks of age-related disease and optimize health, and is not a diet specifically for weight loss. Nonetheless, many people will lose weight on it. Stabilizing blood sugar by eating low-glycemic-load meals, eating lean protein with healthy fats, drinking plenty of water, and having high quantities of fiber from fresh fruits and vegetables all contribute to increased metabolism, which helps the body burn fat rather than store it.
The anti-inflammatory diet counteracts the chronic inflammation that is a root cause of many serious diseases that become more frequent after age 60. Normally, inflammation occurs in response to injury and attack by germs. It is marked by local heat, redness, swelling, and pain, and is the body's way of getting more nourishment and more immune activity to an area that needs them.
But inflammation isn't always helpful. It also has destructive potential. We see this when the immune system mistakenly attacks normal tissues in such autoimmune diseases as type 1 diabetes, rheumatoid arthritis, and lupus. And we now know that inflammation also plays a causative role in heart disease, Alzheimer's and Parkinson's diseases, as well as other age-related disorders, including cancer.
The anti-inflammatory diet gives you a healthy balance of omega-3 and omega-6 fatty acids. Most people consume an excess of omega-6 fatty acids from which the body synthesizes hormones that promote inflammation. These fats are found in oil-rich seeds and the oils extracted from them, which are used in almost all snack foods and fast foods. Omega-3 fatty acids have an anti-inflammatory effect and are found in oily fish, walnuts, flax, hemp, and to a smaller degree in soy and canola oils and sea vegetables. In addition to correcting the balance between omega-6 and omega-3 fatty acids, the anti-inflammatory diet eliminates consumption of margarine, vegetable shortening and partially hydrogenated vegetable oils - all of which promote inflammation.
Carbohydrate foods also influence the inflammatory process. In the body, chemical reactions between the sugars and protein produce pro-inflammatory compounds called AGEs (advanced glycation end products). You can moderate this process by keeping blood sugar low and stable. That means eating less bread, white potatoes, crackers, chips and other snack foods, pastries, and sweetened drinks, less refined and processed foods, and by avoiding fast foods and products made with high fructose corn syrup. Instead, eat more whole grains, beans, sweet potatoes, winter squashes and other vegetables and temperate fruits such as berries, cherries, apples, and pears instead of tropical fruits such as bananas, pineapple, mango and papaya.
As far as protein is concerned, eat less meat and poultry, both of which contain pro-inflammatory fats, and more vegetable protein (soy foods, beans, lentils and other legumes), whole grains, seeds, and nuts. If you eat fish, choose the oily varieties that give you omega-3s (wild Alaska salmon, sardines, herring, and black cod). For a thorough discussion of the role of inflammation in initiating and promoting disease (and details of the anti-inflammatory diet), I suggest reading my book, Healthy Aging, or joining Dr. Weil on Healthy Aging, which features anti-inflammatory eating guides.
Andrew Weil, M.D.