Jonny Bowden, author, nutritionist and weight loss coach cuts through all the misconceptions about diet and fitness to help you transform your body, your health and your life.

There's no doubt that genes have something to do with your weight. But not nearly as much as you might think.

According to a new study, lifestyle choices have a lot more to do with insulin resistance and obesity than heredity does. What you do -- or don't do -- can actually "turn on" these genes (or render them inactive).

Insulin resistance is a condition in which the body doesn't process sugar well, and it often leads to diabetes, obesity, heart disease or all three. But with all the talk of finding "genes" for these conditions, we often forget an important fact: Genes interact with the environment.

A new study from the University of Helsinki found that a sedentary lifestyle actually impairs the functions of certain genes that are related to insulin resistance in obese people. The study looked at 14 pairs of identical twins in which only one twin was obese (the other was normal weight).

In every single case, the normal-weight twin exercised and was fit, despite sharing identical genes with the obese, insulin-resistant twin.

Remember: Genes load the gun, but environment pulls the trigger. Lifestyle and diet choices actually affect what your genes do. In many cases- -- if not most -- you have the choice to "turn them on" or "turn them off."