Unintentional weight loss can occur because of an inadequately nutritious diet relative to a person's energy needs (generally called malnutrition). Disease processes, changes in metabolism, hormonal changes, medications or other treatments, disease- or treatment-related dietary changes, or reduced appetite associated with a disease or treatment can also cause unintentional weight loss.[26][27][28][32][33][34] Poor nutrient utilization can lead to weight loss, and can be caused by fistulae in the gastrointestinal tract, diarrhea, drug-nutrient interaction, enzyme depletion and muscle atrophy.[28]
Anaerobic exercise, on the other hand, primarily uses sugar as its fuel. This doesn’t mean that it’s not good for weight loss, though. Anaerobic exercise helps build muscle, and as we explained above, this will help you burn calories even when you’re resting. Anaerobic exercises are generally high intensity, for example sprinting and weight lifting. 
Are you like Old Faithful when it comes to your morning walk or evening jog? Know this: The more you do an activity, the more your body adapts to it, so you burn fewer calories. If you want to light a fire under your metabolism, consider cross-training. For example, if you normally walk, try biking instead. "Since you're not used to working all those different muscles, it's a more intense workout, which can translate into a greater metabolic after-burn because your body is working harder to recover and get oxygen to all your tissues," says Carol Espel, M.S., an exercise physiologist for Equinox Fitness Clubs in New York City.
It's a one-time investment you'll never regret. Here's why: Strength training builds lean muscle tissue, which burns more calories — at work or at rest — 24 hours a day, seven days a week. The more lean muscle you have, the faster you'll slim down. How do you start strength training? Try some push-ups or a few squats or lunges. Use your free weights to perform simple bicep curls or tricep pulls right in your home or office. Do these exercises three to four times per week, and you'll soon see a rapid improvement in your physique.
It’s true that types of foods you eat may, over time, affect your metabolic profile, so they may also matter in this way, but when it boils down, sticking to any reduced-calorie diet will create the energy deficit needed to lose weight. So the point is not to question what a calorie is, but rather to understand that we need to “trade up” our foods, says Katz – exchange the very dense, calorie-packed foods for foods that are less calorie-dense and more nutritionally dense: these are the ones that are bulkier, less energetically rich, have more or higher quality protein, are lower on the glycemic index, and more fibrous.
Health issues stem from obesity, so getting a handle on weight loss leads to healthier futures.  Weight loss calculator brings precision to weight loss efforts, estimating the number of calories required for various weight scenarios.  The feedback provided illustrates caloric intake needed to maintain present weight as well as what would be necessary for gaining or losing weight.
You can lower your LDL or “bad” cholesterol with healthier food and medications. But it’s harder to raise levels of the “good” kind of cholesterol, HDL. That’s the type that clears bad LDL from your blood, so the more you have, the better. Exercise and losing body fat can get you into the ideal HDL range: above 60 mg/dl, which lowers your odds of having heart disease.