Overweight does not necessarily equal unhealthy.

There are actually plenty of overweight people who are in excellent health .

Conversely, many normal weight people have the metabolic problems associated with obesity .

That's because the fat under the skin is actually not that big of a problem (at least not from a health standpoint, it's more of a cosmetic problem).

It's the fat in the abdominal cavity, the belly fat, that causes the biggest issues .

If you have a lot of excess fat around your waistline, even if you're not very heavy, then you should take some steps to get rid of it.

Belly fat is usually estimated by measuring the circumference around your waist. This can easily be done at home with a simple tape measure.

Anything above 40 inches (102 cm) in men and 35 inches (88 cm) in women, is known as abdominal obesity.

There are actually a few proven strategies that have been shown to target the fat in the belly area more than other areas of the body.

Here are 6 evidence-based ways to lose belly fat.

1. Don't eat sugar and avoid sugar-sweetened drinks

Added sugar is very unhealthy.

Studies show that it has uniquely harmful effects on metabolic health.

Sugar is half glucose, half fructose, and fructose can only be metabolized by the liver in any significant amount .

When you eat a lot of refined sugar, the liver gets overloaded with fructose, and is forced to turn it all into fat .

Numerous studies have shown that excess sugar, mostly due to the large amounts of fructose, can lead to increased accumulation of fat in the belly .

Some believe that this is the primary mechanism behind sugar's harmful effects on health. It increases belly fat and liver fat, which leads to insulin resistance and a host of metabolic problems .

Liquid sugar is even worse in this regard. Liquid calories don't get "registered" by the brain in the same way as solid calories, so when you drink sugar-sweetened beverages, you end up eating more total calories .

Studies show that sugar-sweetened beverages are linked to a 60% increased risk of obesity in children, per each daily serving .

Make a decision to minimize the amount of sugar in your diet, and consider completely eliminating sugary drinks.

This includes sugar-sweetened beverages, fruit juices and various high-sugar sports drinks.

Keep in mind that none of this applies to whole fruit, which are extremely healthy and have plenty of fiber that mitigates the negative effects of fructose.

The amount of fructose you get from fruit is negligible compared to what you get from a diet high in refined sugar.

If you want to cut back on refined sugar, then you must start reading labels. Even foods marketed as health foods can contain huge amounts of sugar.

2. Eating more protein is a great long-term strategy to reduce belly fat

Protein is the most important macronutrient when it comes to losing weight.

It has been shown to reduce cravings by 60%, boost metabolism by 80-100 calories per day and help you eat up to 441 fewer calories per day.

If weight loss is your goal, then adding protein is perhaps the single most effective change you can do to your diet.

Not only will it help you lose, it can also help you avoid re-gaining weight if you ever decide to abandon your weight loss efforts.

There is also some evidence that protein is particularly effective against belly fat.

One study showed that the amount and quality of protein consumed was inversely related to fat in the belly. That is, people who ate more and better protein had much less belly fat.

Another study in Denmark showed that protein was linked to significantly reduced risk of belly fat gain over a period of 5 years .

This study also showed that refined carbs and oils were linked to increased amounts of belly fat, but fruits and vegetables linked to reduced amounts.

Many of the studies showing protein to be effective had protein at 25-30% of calories. That's what you should aim for.

So make an effort to increase your intake of high protein foods such as whole eggs, fish, seafood, legumes, nuts, meat, dairy products and some whole grains. These are the best protein sources in the diet.

If you struggle with getting enough protein in your diet, then a quality protein supplement is a healthy and convenient way to boost your total intake.

4. Eat foods rich in fiber, especially viscous fiber

Dietary fiber is mostly indigestible plant matter.

It is often claimed that eating plenty of fiber can help with weight loss.

This is true, but it's important to keep in mind that not all fiber is created equal.

It seems to be mostly the soluble and viscous fibers that have an effect on your weight.

These are fibers that bind water and form a thick gel that "sits" in the gut.

This gel can dramatically slow the movement of food through your stomach and small bowel, and slow down the digestion and absorption of nutrients. The end result is a prolonged feeling of fullness and reduced appetite.

One review study found that an additional 14 grams of fiber per day were linked to a 10% decrease in calorie intake and weight loss of 2 kg (4.5 lbs) over 4 months.

In one 5-year study, eating 10 grams of soluble fiber per day was linked to a 3.7% reduction in the amount of fat in the abdominal cavity, but it had no effect on the amount of fat under the skin.

What this implies, is that soluble fiber may be particularly effective at reducing the harmful belly fat.

The best way to get more fiber is to eat a lot of plant foods like vegetables and fruit. Legumes are also a good source, as well as some cereals like oats.

Then you could also try taking a fiber supplement like glucomannan. This is one of the most viscous dietary fibers in existence, and has been shown to cause weight loss in many studies.

5. Exercise is very effective at reducing belly fat

Exercise is important for various reasons.

It is among the best things you can do if you want to live a long, healthy life and avoid disease.

Getting into all of the amazing health benefits of exercise is beyond the scope of this article, but exercise does appear to be effective at reducing belly fat.

However, keep in mind that I'm not talking about abdominal exercises here. Spot reduction (losing fat in one spot) is not possible, and doing endless amounts of crunches will not make you lose fat from the belly.

In one study, 6 weeks of training just the abdominal muscles had no measurable effect on waist circumference or the amount of fat in the abdominal cavity .

That being said, other types of exercise can be very effective.

Aerobic exercise (like walking, running, swimming, etc) has been shown to cause major reductions in belly fat in numerous studies.

Another study found that exercise completely prevented people from re-gaining abdominal fat after weight loss, implying that exercise is particularly important during weight maintenance .

Exercise also leads to reduced inflammation, blood sugar levels and all the other metabolic abnormalities that are associated with central obesity.

6. Track your foods and figure out exactly what and how much you are eating

What you eat is important. Pretty much everyone knows this.

However, surprisingly, most people actually don't have a clue what they are really eating.

People think they're eating "high protein," "low-carb" or whatever, but tend to drastically over- or underestimate.

I think that for anyone who truly wants to optimize their diet, tracking things for a while is absolutely essential.

It doesn't mean you need to weigh and measure everything for the rest of your life, but doing it every now and then for a few days in a row can help you realize where you need to make changes.

If you want to boost your protein intake to 25-30% of calories, as recommended above, just eating more protein rich foods won't cut it. You need to actually measure and fine tune in order to reach that goal.