Diet and Nutrition expert Laura Brown discusses why no one diet works for everyone, and discusses how to create sustainable, lasting weight loss without dwelling on calories, carbs, fats, proteins, restrictions and lists of good and bad foods, in a way that is flexible, fun and free of denial and discipline.

There are many differing dietary theories on the market today. It doesn’t require a very close inspection to notice the many contradictions between these theories and to wonder how it could be that the field of experts is so far apart on what works and what’s healthy.

The simple answer to that question is that no one diet works for everyone. Some people swear by Barry Sears’ Zone Diet and some couldn’t follow it if their life depended on it. If D’Adamo’s Blood Type diet worked for me, why was I hearing that some people couldn’t stand it? Some people looked and felt great on Atkins; others said it almost put them in the hospital.

It turns out that we are looking at the results of something called “Bio-individuality”. It’s a new understanding that goes beyond the flavor-of-the-month approach to weight loss. Bio-individuality, a theory put forth by Roger Williams in 1956 in a book called Biochemical Individuality, says that every person is unique, and the diet that will work best for them is also very unique and individualized. Just as we all have different personalities, finger prints, DNA and other characteristics, we all have different dietary needs. And they change over time as we change and grow, and as we move through the seasons, and through the years. We have different dietary needs at twenty than we do at forty and sixty. And they’re all determined by the stamp of our bio-individuality.

Ancestry - One of the factors determining our dietary needs is our ancestry. If your ancestors come from Italy and southern Europe, the Mediterranean type diet rich in olive oil and nuts, abundant in fruits & vegetables, whole grains, fish, poultry, dairy and red wine, is likely to work for you. Ancestry also plays a part in determining the foods that are not good for you. If you’re of African descent, where green vegetables, grains, beans and sweet potatoes were consumed daily, but milk was usually not available, it makes sense that you would be lactose intolerant, as many people of African descent are. If you are having issues with a particular food or class of foods, it may help to look to your ancestry for clues.

Blood Type - Another major factor is bio-individuality is our Blood Type. Popularized by D’Adamo in his Blood Type Diet, the theory is that each of the blood types (A, B, AB and O) developed at a certain time period in human evolution, each with unique ways of eating and living. For example, type A developed during a period of agrarian communities, and type As do well with lots of vegetables, fruits and grains. Type O, on the other hand, occurred in the midst of a hunter-gatherer culture, when people ate more meat. Type Os often find that more protein is essential in their diets. The differences in diet between blood types are related to chemical differences in the body, resulting in varying interactions between substances in food, and your blood. So if you’re a type AB, and you eat foods that are chemically similar to type O, they can actually irritate your system, just as getting a transfusion of the wrong blood type would. This is why it’s sometimes said that one man’s food is another man’s poison.