Stored body fat is the last thing your body will use as fuel. The whole reason we store extra calories (that can come from anything) is to have a back up or reserve. The only way body fat can be effectively used as fuel Is If blood sugar is stable, and the body is using more fuel than is being supplied! This is what keeps most people from burning fat.
I often have people tell me " I run all the time", or " I hardly eat anything, but I'm still not losing fat." The reason is because they have unstable blood sugar, and/or they exercise at the same level of intensity all the time (usually a moderate level). Remember that the two most important factors when it comes to burning fat are stable blood sugar and lack of hard physical activity.
Let's look at these two factors more closely. Blood sugar levels are directly affected by meal frequency and food choices. Eating small, balanced meals/snacks every 2-3 hours is one way to help stabilize blood sugar. Small frequent feedings (provided they contain only enough calories necessary for the level of activity at that time) force your body to adapt or get used to having food, which will keep blood sugar fairly stable. This makes it less likely for your meals to be stored as fat.
What you eat also plays a big part in blood sugar. For example, juice increases blood sugar quickly forcing it to skyrocket as opposed to vegetables, which burn at a much slower rate. Avoid foods containing large amounts of sugar such as soda, juice, candy, ice cream, table sugar, and other refined foods. Focus on whole grains, vegetables/fruits, lean proteins, and un-saturated fats (for more info on nutrition see my Healthy Eating Guidelines Packet).
Unstable blood sugar is something that can do serious damage to your body in addition to increasing body fat levels, such as hormonal discrepancies and Type II Diabetes. Most people are totally unaware as to what blood sugar is or what it does in your body.
Activity level is the other major factor, which prevents a lot of people from making any progress! Most people are misinformed and still think they need to sweat to burn fat. This is totally not the case! I have had great success with clients losing fat with out even going to the gym! Again, all that is necessary is that blood sugar is stable and that the individual is burning more calories than they are supplying. So what does that mean? Eat small, balanced meals or snacks every 2.3 hours, increase muscle tissue with progressive strength training, and stay active (for more info on progressive strength trainings see my article entitled Success with Strength Training)!
An easy way to stay on track is to ask your self before every meal or snack "what will I be doing for the next few hours?" If you are going to be at work and not that active then your body doesn't need a lot of calories. Don't forget that any extra calories (whether from vegetables or pizza) that don't get used will be stored as fat!
MATCH YOUR EATING TO YOUR ACTIVITY LEVEL!
Another major problem is the common misconception that your metabolism slows down as you age. This has been proven to be incorrect with hundreds of studies! Your metabolism slows down due to a loss of muscle tissue, and that is a direct result of a lack of strenuous physical activity. That is why it is so important to due some form of strength training.
I also recommend performing 2-3 high intensity cardiovascular workouts per week on non-consecutive days. These workouts should be an 11 on a scale of 1-10 (level of effort or intensity)! These hard cardiovascular workouts are great for increasing metabolism for 4-12 hours or more! Both strength training and hard cardiovascular workouts deplete glycogen (stored muscular energy).
A large portion of your meals following that workout will be used to replenish the glycogen (muscular energy) that was used to fuel that workout. This also means you are a lot less likely to store any excess calories as fat! Plus, if you eat well following that workout, your body will start to metabolize fat for fuel.
I have used this basic information to change people's lives! By making just a few small changes I've had people burn on average 1-2 pounds of fat per week! Just imagine what that means over the course of a few weeks or months! The human body is only capable of metabolizing 2-3 pounds of fat per week with a miracle. So a more realistic goal would be 2-6 pounds in a month. Not exactly what people want, but it's better than not making any progress at all! This information is what stands between most people and their goals.