Obesity is easy to determine. Anyone with a Body Mass Index over 30 is obviously overweight and will appear to be so. What is a little more difficult is teaching people how to control their weight, and unfortunately I've found that most people have neither the math skills nor the inclination to do so. But I'll give an example below anyway for those who are interested:

Everyone should aim to have a BMI less than 25. Calculate your healthy weight from the BMI formula as:

Maximum Healthy Weight = 25 * (height in meters)^2

This is just an approximation, but all the literature and scientific studies state basically the same thing, within a few pounds accuracy. People with a BMI over 25 have a marked decrease in health and longevity.

So what if you're overweight? Well, you can't just stop eating. There is a minimum number of Calories that your body needs each day for your organs to function (heart, kidneys, liver, nervous system). This is called the Basal Metabolic Rate, and is calculated from the following formulas:

Men: BMR = 66.4730 + ( 13.7516 x weight in kilos ) + ( 5.0033 x height in cm ) - ( 6.7550 x age in years )

Women: BMR = 655.0955 + ( 9.5634 x weight in kilos ) + ( 1.8496 x height in cm ) - ( 4.6756 x age in years )

This will tell you the minimum Calories you need each day just to stay alive, laying in bed, and not moving. But even people with a sedentary lifestyle will burn more calories each day than this indicates. Once you calculate your BMR, you should plug it into the Harris-Bennedict Equation, which adds an activity factor to BMR as follows:

1. If you are sedentary (little or no exercise) : Calories = BMR x 1.2
2. If you are lightly active (light exercise/sports 1-3 days/week) : Calories = BMR x 1.375
3. If you are moderatetely active (moderate exercise/sports 3-5 days/week) : Calories = BMR x 1.55
4. If you are very active (hard exercise/sports 6-7 days a week) : Calories = BMR x 1.725
5. If you are extra active (very hard exercise/sports & physical job or 2x training) : Calories = BMR x 1.9

This will tell you roughly how many Calories you need each day to MAINTAIN your current weight. But to lose weight you need a Calorie deficit. A 4100-Calorie deficit per week means you will shed 1 pound of fat per week. That's about 580 Calories per day. You can cut back on eating (count calores), or you can exercise more. But be careful with dieting. For example, the American College of Sports Medicine stresses that for a fit male between 18-40, daily Calorie levels should never drop below 1800, and that even this is quite low. So you can't just starve yourself, or you could end up in hospital. Exercise however can drive your calorie burn up higher without starving yourself, and this is a healthier way to lose weight.

My recommendation is:

Use a spreadsheet to create a meal plan. Add up the calores and make sure it is at least equal to, say, BMR times 1.2. Don't forget to add Calories from fruit juice, milk, and other liquids, they are quite a significant contributor. After that, stick with it. Don't pay any attention to the "Food Pyramid". IMO it's crap, and does not encourage people to count calories, and that's the key. Once you figure out a meal plan according to the BMR and Harris-Bennedict equations you may find your food bills drop significantly. This is a side-benefit.

Then exercise daily. Hop on a stationary bike, or a stairmaster, or a treadmill, and do a straight 500-1000 Calorie burn. Might take 30-60 minutes. You don't even have to push yourself. Calorie burning can be achieved with either high-intensity exercise or low-intensity exercise. For weight-loss purposes it doesn't matter. The bike for example probably has a "power tap" and can tell you EXACTLY how many calories you've burned. It calculates it automatically based on how much electricity you've generated divided by human metabolic efficiency of around 0.24. Power taps are cheap too, near where I live there is a store that sells them for about $30 bucks.

Some people are more athletic. They push themselves while exercising, not just to achieve a certain calorie expenditure and a healthy body weight, but also to achieve a certain measure of cardiovascular conditioning. If this is you, there are a number of metrics that you can use to measure cardio fitness. And even if you don't have an eye on running a marathon or competing in the olympics, cardio metrics are an excellent way of charting improvements in general health. Seriously, if one day you run a certain distance/time with your heart rate at 165, and the next day you can run a bit faster, or a bit further, and your heart rate was the same or lower, that is IMPROVEMENT, and a serious motivational factor in keeping up with a workout program. Heart Rate Training is for people with athletic goals. If you want to go this route, I would get both a power tap and a heart rate monitor. You should be able to buy the latter for about $65.

I also recommend buying calipers to measure skin fold thickness. This is usually done to estimate body fat percentage, but is very inaccurate. There is no point in doing anything except tracking how skin fold thickness changes over time. If you go the body-building route then your body weight might be a bit higher than indicated by BMI. But as long as your skin fold thickness is decreasing then your body fat is decreasing. This is another great way to chart progress and boost motivation. Canadian Tire and other hardware stores sell plastic calipers for about $7 bucks.

So for people who are serious about losing weight, there are all kinds of things that you can do. For policy makers who want to restrict free health care to people who are sick because of "no fault of their own", they need to educate the general public properly about fitness. The Food Pyramid just doesn't cut it. In addition, they may want to make sure that people have enough time in their day to exercise. A national limit on daily work hours, say a 9-hour work day, would be particularly beneficial, allowing people enough time to exercise, or do other things like pursue a hobby or spend time with family. Unfortunately, in Canada we see a trend toward 12-hour work days, or even longer. Not only are employers monopolizing people's time, the trend toward a decline in health and increase in obesity is obvious.