THAT was an awkward doctor's visit: Being on the other side

I went in to see my primary care physician last week... and learned I had gained around 10 lbs in the last few months. The conversation went like this:
Doctor: "So... you gained 10 lbs since I last saw you... you're still ok, but is this becoming a trend?"
Me: "Oh...I wore shoes on the scale this time."
Doctor: "Shoes don't weigh 10 lbs..."
Me: "I...I...also had my wallet and keys..."
Doctor: "We're still looking at at least 5 lbs..."
Me: "It's all muscle!!!"
Doctor: "Oh have you been weight training?"
Me: "Yeah! See?" <flexing so he could see my new muscles>
Doctor: "It's not all muscle... what have you been eating? Are you still exercising?" 

AAAHHHHHH!!! How did this happen? After all the time I spend counseling patients on diet and exercise... it was surreal to be on the other side of it. I felt like a kid being scolded, and I came up with one excuse after another. I wonder if that's how all patients feel when they sit on the exam table: this feeling of being in trouble and not knowing what to do but minimize the problem with excuses. I wonder if I make my patients feel like that. Moving forward, I'd like to be more aware of trying to make lifestyle change discussions more inspirational instead of just pointing out problems. I want my patients to leave the room going, "I'm going to do it" instead of thinking, "I wasn't doing it right..." I'm just not entirely sure how to accomplish this yet. The doctor-patient dynamic inherently makes these discussions so difficult. It is a power dynamic similar to getting sent to the principal's office, and even my first reaction was to go on the defensive. So how do you bring out the pal in princiPAL (saw that on a sign once as a way to remember the different between principle and principal... stuck with me all these years), for the doctor-patient relationship? 

On another note... I'm apparently a non-compliant patient too... At my last visit, my doctor discovered I had a heart murmur and ordered for me to get an ECHO just to see what it was. I wasn't overly concerned about it given that I have been able to run and do Crossfit without feeling light headed or anything... and completely forgot about it. "So did you get the ECHO done?" "What ECHO?" "Last time, we heard a murmur and I ordered an ECHO" "Oh you did? I didn't know that...so...yeah...no.". 

I hope my patients are better patients than I.