It’s something every fitness guru tells you: exercise boosts your metabolism, increasing your body’s ability to burn fat for hours after your workout is finished. It’s a philosophy that many of us – myself included! – clung to, but a new study found that weight loss resulting from exercise tends to be lower than expected.

This study found that sedentary Westerners actually have the same metabolic rate as the constantly-moving Hadza tribe of hunter-gatherers in Tanzania. In other words, what keeps them fit isn’t exercise, it’s nutrition. They’re lean because they don’t consume the calorific junk food that many Westerners do, not because they’re more physically active than Westerners.

As children everywhere toil away at their summer jobs, Ancestry.co.uk has taken a look back at the child workforce of Victorian Britain. Think your summer jobs were tough? Think again. Victorian children’s jobs were nothing like the newspaper routes, babysitting, camp counselor, and dog-walking jobs kids have these days. Children 160 years ago took on far more unusual and dangerous occupations.

Eighteen million census records reveal that Victorian youngsters no older than 15 had jobs assisting surgeons and working in mines. The most common occupations for children were domestic servants, shoemakers, and nurses, followed by tailors and hat sellers. Now it seems nearly impossible to imagine a 14-year-old assisting at a surgery, but it was a common reality in Victorian Britain.

Losing weight is one thing. Maintaining weight loss is quite another. And for many people, keeping the weight off is an even bigger challenge than losing it in the first place.

So what’s the secret?

A new study published in the Journal of the American Medical Association put three diets to the test to determine which holds the key to lasting weight loss. The researchers studied 21 overweight and obese adults who had recently lost at least 12.4% of their body weight. After their initial weight loss, the participants were put on a cycle of three diets, each lasting four weeks, to examine which was the most effective for weight maintenance.

New York Times reporter Rachel Swarns traced Michelle Obama’s family history in her new book, American Tapestry: The Story of the Black, White and Multiracial Ancestors of Michelle Obama, and made some fascinating discoveries about the First Lady’s ancestry. Swarns calls the story, which stretches all the way back to the Revolutionary War, “very American.”

"There is this real fascination with family history, with genealogy, with DNA testing," Swarns says. "I think the First Lady has always had some curiosity about her own family tree."

Everyone is worried about losing weight to look good on the beach. But how about going to the beach to lose weight?

Threw you for a loop with that one, didn't I?

Here are a few suggestions for keeping fit while enjoying the sunny summer weather in the sand:

“Weight management as data-driven as the rest of our lives” – that’s the promise of Retrofit, a company that pledge to revolutionize the health industry by taking the best that modern science has to offer and transforming it into a weight loss plan for the 21st century.

The company promises to help clients lose at least 10% of their current weight and keep it off through the end of the 12-month program. If a client upholds all commitments but doesn’t meet their personalized weight loss goal, Retrofit offers a second year of the service at no charge.

Here’s what sets it apart: the Retrofit program is all about technology. Clients use hi-tech wireless Fitbit activity trackers and a wi-fi scale to monitor behavior patterns and review the results with a team of personal wellness experts. The client makes four commitments: