Have fitness questions? Fitz has your answer. Our ThatsFit.com fitness expert -- and now your own virtual personal trainer -- will help you get fit, increase your overall health and do it in a fun way. Drop your questions here in the Comments section below and we'll choose two per week to publish on That's Fit! Learn more about Fitz here.

Q. Hi Fitz, I am 15 and I weigh 225 pounds. I'd like to lose a lot of weight. For exercise, I fast walk on the treadmill for 15 minutes a day. I try to eat the right foods, but I keep having a temptation to go back to my old habits. I keep trying, but because of my brother's metabolism... he can eat anything. That is not helping me at all. I need help, but I'm afraid that no one will help me because of my weight, so I hope you guys can. Shelby

A. I'm really glad you reached out for help here, Shelby. Being overweight is no fun, especially as a child.....which you are. I struggled with my weight as a teenager too, but thankfully I eventually figured things out. I remember way back then thinking a good weight loss technique was to simply eat fewer Cheetos. My parents never spoke about weight management to me and I simply didn't have much guidance on the subject. I felt bad about myself and desperately wanted to change. Sounds like you're in the same boat.

You're on the right track when it comes to exercise and eating right. We just have to improve upon your present efforts. Fifteen minutes on the treadmill is a great start. I'd like to you to increase your time steadily until you're on that beast for 45 to 60 minutes most days of the week. Strive for six days. Then slowly incorporate strength training. You can do so with equipment at a gym, a video at home, or via old fashioned push-ups, squats, lunges and crunches. Building muscle will not only help you lose weight, but it will help you to genuinely feel more fit.

In my book, eating habits play a greater factor in weight loss than exercise. I absolutely want you to do both, but you need to understand how vital your food choices are to your success. You could consume a thousand calories in less than ten minutes, yet it may take you three hours to burn a thousand calories. Food counts. Choose nutritious produce, whole grains, lean meats, and lean dairy. Avoid useless white foods like, sugar, flour, white rice and pasta. Drink water or other calorie free beverages. You can do that!

As far as your brother goes....forget about him. You can't base your success or failure on anyone else in the entire world other than you. I don't care if he devours 900 cookies. You stick with the healthy stuff. His habits and/or metabolism are irrelevant. Of course, it would probably be fun to eat whatever we wanted with no impact on our size. But if that's not your gift, then it's not. Don't cheat yourself by making excuses about your brother.

Weight loss is a day by day, moment to moment effort, Shelby. You don't have to be perfect. You do have to be consistent. If you exercise religiously and then miss a few days.....not such a big deal. If you make a habit of always seeking low fat and nutritious food 90% of the time, a piece of cake at a birthday party won't hurt you either. Plan your day, schedule in workouts, and keep a food diary. I recommend stepping on the scale naked, once a week in the morning. The scale will help you gauge whether you're having weight loss success or not. A stagnant scale for a week or so is common. If however, you don't lose any weight for more than two weeks....I'd re-evaluate or increase your efforts.

Keep me posted on your success Shelby. I'm so excited to see what's in your future. Fitz!

Q.Yo Fitz! Just curious. What is your favorite piece of fitness equipment? Mark.

A. Great question Mark. I have an instant answer in my mind and am happy to share it with you. The X-ertube is my favorite. Tubing is great for cardio, strength and flexibility training. It's dirt cheap and can fit in my purse. I use tubing all the time personally, and torture both my beginner and advanced students with it. My favorite brand of tubing is SPRI. My favorite color/level is green.

Punches & Kicks,

Fitz

Fitzness.com

Note: The content presented in this Q. & A section is for informational purposes only and should not be viewed as medical advice or substitute for professional medical care.