In this week’s nutrition news: Grass-fed milk is better for your heart, get paid to lose weight and why you shouldn't eat everything you see on TV.

Both asthma and obesity are much more common than they were 30 years ago, and a new study confirms a link between the two. Researchers examined about 4,500 people and found that 12 percent of obese folks had asthma, compared with 6 percent of those at a normal body weight. The probability of asthma also rose as BMI (body mass index) went up. More studies are underway to find out why obesity increases the likelihood of asthma.

How would you like to get paid to lose weight? About a third of U.S. companies are offering employees financial incentives to shed pounds and get healthier. Although these types of programs are very successful now, the long-term results are unclear. The few studies that examine employee’s long-term success found that the average weight lost was a little over a pound.

Protein shakes are popular all over, from athletes to college students to my dad (he loves his shakes).  But a recent Consumer Reports investigation found that protein shakes aren’t always as healthy as they seem. They examined 15 drinks for the potentially toxic metals arsenic, cadmium and lead and found them in all the tested samples. Although the levels were below FDA regulation, they concluded that people who consume protein drinks daily are at risk for toxicity. Overconsumption of these drinks (specifically of protein) has also been known to lead to dehydration and digestive issues, increased risk of osteoporosis and even kidney problems. The bottom line: drink in moderation.

Seen any food ads on TV lately? A recent study published in the Journal of the American Dietetics Association found that a diet consisting of foods advertised on TV would have a whopping 25 times more sugar and fat than the recommended daily amounts. It would also be lacking in vegetables, fruits and dairy products (fewer than half the recommended servings of each). So next time you’re watching a food commercial, think about what they’re trying to sell you -- odds are, it isn't so good for you.

Organic or conventional milk?  Along with the back-and-forth over raw milk, it's a hotly debated issue. Previous studies have shown that milk from cows who are grass fed produce five times more heart-healthy unsaturated fat called conjugated linoleic acid (CLA) than milk from cows fed a diet of processed grains. Researchers at the Harvard School of Public Health set out to determine the benefits of eating foods with higher amounts of CLA’s. After examining 4,000 people, they found those with the highest levels of CLA’s had a 36-percent lower risk of heart attack when compared to those with the lowest levels. So next time you're at the market, choose the grass-fed cows milk. Want to know more. Read our post about the differences between organic and grass-fed cow's milk to find out more.

Toby Amidor, MS, RD, CDN, is a registered dietitian and consultant who specializes in food safety and culinary nutrition. See Toby's full bio »