Well first of all I just want to say that I think it's awesome you are using your riding as motivation for your fitness. People of all shapes and sizes are beautiful, but fitness can help a lot in your everyday life.
Last year, sometime before Easter, I remember being with friends and we were just sitting around eating unhealthy sweet food. Now, I still like the rewarded dessert and unhealthy snack, but it was that night I remember feeling frustrated with myself... just ready to change the lifestyle that I had grown to know. I don't think I was riding at that point, unless I'm forgetting.
Since then, I've gone through times of "YES I LOVE EXERCISE WOOO" and "are you kidding me, I love to just relax and watch netflix." Now, it's good to have relaxation days as well, but it's important to lead an active and healthy lifestyle... and to the riding lifestyle feeling this way is important because the barn life is demanding (certainly in a good way).
Recently I joined a gym with my sister. Between my trips to the barn and my trips to the gym (I don't go every day but I try to go at least a couple days a week) I feel as though I'm getting in better shape. I also realized, at that time last year, that I need to change my feelings about eating.
Eating is a weird concept. So, yeah, it's fine to treat yourself to things every now and then. And if you wait a year to have dessert, it's especially difficult because then your sweet tooth overtakes all of your feelings (so treat yourself every now and then so that doesn't happen hah). And getting crazed about what your weight is and counting calories isn't the answer, and I know it wasn't for me. But if you are passionate enough to say, "hey, i want to change for the well being of my horse and myself" ANYTHING is possible. Just be conscious of your food, do a little research now and then, maybe keep a food journal if you feel it would help but don't infatuate yourself with the amount of calories you eat... remember, carbs are a short term source of energy, starches take a little more time for the body to use. Carbs aren't the enemy, only in excess can they be harmful! And as far as working out goes, the gym is awesome for me... I have found a lot of happiness in the stationary bike and many calories burnt, as well as some of the other equipment. I don't know about you guys but my horse is my best friend and riding is such a God-given passion of mine, the whole riding thing makes me so motivated to gain muscle and shed unnecessary pounds to increase my fitness and riding experience.
Best of luck to everyone in your riding journeys (:
God bless, englishaqh (: