There have been some great comments posted this week about nutrition and weight loss during PT. I'm thrilled to see chrisrawk join me in my fitness endeavor and Eric has provided a great suggestion for eating well without depriving yourself. It's much easier to stay motivated when you have a fitness buddy to train with, so I'll send you a big "high five" Chris and good luck with your workouts.
You asked a good question about weight loss. The general rule is that if you want to lose weight then your calorie output must be higher than your calorie intake. It's "simple" math, although there is nothing simple about it. Basically it just takes a lot of determination.
You'll have to decide what works with your lifestyle, but I can tell you a little bit about what works for me.
The method that has worked best for me over the years is to start by concentrating on exercise and work on eating habits later. The reason this works for me is because I am much more motivated when I feel good about what I am doing. Generally exercise makes me feel good, and depriving myself of my favorite foods makes me feel grouchy and depressed. Dieting has never worked for me and I don't even bother to try it these days.
The exercise will burn calories and it will speed up your metabolism. By building muscle and by speeding up your metabolism you will find it easier to maintain a healthy weight (as well as a great beach body).
Keep up your fitness routine and when you have gotten over the hard part (muscle soreness, putting aside distractions and making exercise a priority in your day) you will start to look forward to the workouts. At this point, your body will start telling you what it wants you to eat. Your body will tell you to drink more clear fluids, it will tell you to cut down on caffein, it will tell you not to feed it high fat foods. This sounds crazy, but I find that when I am serious about exercising my eating habits change without much effort.
It's also a good idea to make changes slowly so that you don't feel deprived. It is easy to make small changes such as fixing your coffee with only one spoon of sugar instead of two, making your sandwich with butter on one piece of bread instead of both, using less salt, etc.
The timing of your meals can set you up for success, as well. By taking in a lot of food early in the day you will be less likely to get the munchies at night. I like to eat two little breakfasts and a good sized lunch which helps me resist the urge to nibble all night on treats.
Making your early meals more robust also helps. Having soup with your lunch will help give you a nice "full" feeling without taking in too many calories. Spicing up the flavour of foods also helps you feel more satisfied. Some healthy ways to do this are to add some tasty salsa or tangy cheese to your meals to fire them up a bit.
Please let me know what is working for you and maybe I'll pick up some ideas that I can use.