Are there any positives or negatives to weight management by only exercising, and not dieting? I know it’s possible, and very doable. As with an intense workout routine your daily calorie needs increase substantially. My primary concern is physique, and how my body will start taking shape as I loose the fat.
It depends on how you’re using the word "diet". Good nutrition and health go hand-in-hand, and any successful weight loss/health gain program will include a change in the diet that got a person there in the first place. If you wish to be successful in the long-term, dietary changes to need to be made if you’re diet is unhealthy in the first place.
However, when talking about fad diets or crash diets, those are pure bunk and have been shown time and again they do not work. The goal of any program should always be good health for the lifespan, that is the only way it can truly stick.
Look at it this way, our body has to get nutrition from somewhere, and the only place is what we give it, and if we’re giving it a lot of junk, that’s the only material it has to build from, and junk will only cause the end product to be weaker than it could otherwise be. So if the diet consists of cookies and ice cream, what do you suppose your body will have from that to build on as compared to a diet of fresh veggies, whole grains, lean proteins and healthy fats?