There are many issues that should be addressed in your question. First and foremost, it is important to take care of your health for yourself rather than for your boyfriend. While relationship advice is beyond the scope of this article, please refrain from being involved in relationships that do not help you to achieve your full potential as a person in every way, and being constantly belittled about your weight is not an acceptable behavior from a significant other.
That being said, meeting with any consultant is not going to help you lose weight unless you make changes to your lifestyle. While I am not sure who a biochemical genetics consultant is, I would be very skeptical of anyone who promises you that losing weight will be simple. The fact of the matter is that so many Americans are overweight because it is hard work to stay in shape, and requires dedication and consistency.
While there are medical therapies available for the obese, the most healthy way for most people is to exercise, watch their diet, and be avoid fast food/high calorie foods. Meeting with a dietician
or your primary care doctor
would be a healthier alternative to any fad.