Ready to bust your BMI — body-mass index — down a few notches? Here are five practical tips from some of the most recent weight loss studies:

Get a fitness app … and use it

Exercise app users are 27 percent more likely to lead active lifestyles compared to those who have never used one, or — and here's the important part — got an app, but stopped using it.

Researchers in a recent joint study across three U.S. universities published in August concluded that "app use leads the user to exercise more consistently for extended time periods, which leads to reductions in BMI."

In fact, the results showed that current app users had an average BMI of 25.16, while both non-users and those who had stopped using an app hovered at an average BMI just below 27.

Get on your feet

There's a reason Apple's watchmakers built in regular reminders to get up on your feet more often. A new study published by Oxford University's European Heart Journal helps explain why.

After studying the daily habits of nearly 800 men and women, all equipped with an activity monitor, researchers found that those who replaced two hours a day normally spent sitting with time up moving around can expect to drop an average of three inches from their waistline and cut 11 percent from their BMI.

Just standing up more often, not even walking around, can improve cardiovascular health.

"We found that time spent standing rather than sitting was significantly associated with lower levels of blood sugar and blood fats," says Dr. Genevieve Healy, a senior researcher at the University of Queensland, Australia, who led the study.

The research is "an important addition to the wealth of scientific evidence highlighting the importance of avoiding sedentary behavior," writes the Mayo Clinic's Dr. Francisco Lopez-Jimenez in a commentary on the study.

It's about how little moments throughout the day add up, he says: "A person walking while at work for two hours, standing for another four hours, and performing some daily chores at home for another hour will burn more calories than jogging or running for 60 minutes."

Adopt a Mediterranean or Japanese diet

Even without cutting calories, you can trim your BMI by 2.6 points — 9 percent — by adopting a Mediterranean diet like that favored in Greece. That's according a University of Nebraska-Lincoln study presented in July at a gathering of scientists in San Francisco.

Adopting a Japanese-style diet is even better for body composition, cutting BMI by three points — or 11 percent — on average.

Diets in both Japan and Greece rely more on plant products and less on red meat than U.S. diets. Japan's diet involves more fish than in the U.S., while in Greece, people eat more cheese and yogurt and less eggs, pork and poultry than Americans.

Smoke/don't smoke

OK, so this one clearly doesn't apply to those currently serving in the military, but veterans and spouses in states where marijuana is legal take note: Pot smokers tend to have trimmer waistlines.

Contrary to munchie-craving stereotypes, regular cannabis use not only reduces body fat and BMI, but also lowers risk of developing diabetes, according to a recent study published in the Journal of Obesity.

The Canadian study compared pot smokers and nonsmokers among nearly 800 Inuit adults, with 57 percent of participants being marijuana users. Non-users had an average BMI of 28.6, while pot users averaged a BMI of 26.8.

Earlier studies have backed this up. Among the most recent, the American Journal of Medicine published similar findings in 2013 from a study of more than 4,600 men and women over five years.

Current marijuana users had significantly smaller waist circumferences than those who did not use pot, even after adjusting for physical activity levels, sex, age, and alcohol and tobacco use.

Meanwhile, another new study loads more ammunition against smoking cigarettes.

Heavy tobacco smokers are more likely to develop — perhaps, ironically — pot bellies (yes, even while the pot smokers are heading the other way and trimming their waistlines).

Researchers at the University of Glasgow report that while regular cigarette smokers may weigh less overall, their fat tends to concentrate in the core, causing bigger stomachs for most.

Drink up before every meal

Drink half a liter of water before each meal and lose nearly 10 pounds in 12 weeks.

That's according to a University of Birmingham study just published in the journal Obesity.

Researchers asked 41 obese individuals to drink two cups of water before every meal over three months.

Another group was asked to just imagine they had a full stomach. Both groups were also given basic information on healthier eating and exercise.

After 12 weeks, the water drinkers who "pre-loaded" before every meal lost an average of 9.48 pounds.

Those who drank water only before one meal or not at all only lost an average of 1.7 pounds.

"The beauty of these findings is in the simplicity: Just drinking a pint of water, three times a day, before your main meals may help reduce your weight," says University of Birmingham professor Dr. Helen Parretti.

"When combined with brief instructions on how to increase your amount of physical activity and get on a healthy diet, this seems to help people to achieve some extra weight loss — at a moderate and healthy rate," Parretti said.

"It's something that doesn't take much work to integrate into our busy everyday lives."