You worked hard to shed pounds, but then it crept right back. It happens. In fact, about 80% of people who lose weight regain it all or more, according to some estimates. It’s a term known by industry experts as ‘weight cycling’ — and colloquially as yo-yo dieting. Here, a look at what this yo-yoing means, why it occurs and smart strategies to keep the weight off for good.

“Basically, any ‘trick’ is not going to work,” says Philadelphia-based weight loss physician Dr. Charlie Seltzer, MD. “We have evolved over tens of thousands of years to store fat. If you try to trick your body into losing fat, it will backfire.”

If you've ever found yourself both terrified and intrigued by what celebs say they eat in a day, same. Who doesn't wonder whether they'd feel as great as Meghan Markle looks if you also began your days with a green smoothie, avoided dairy and sugar (even from fruit), went vegan, and topped your day off with a small piece of 70 percent cacao dark chocolate.

Weight loss can be complicated and sometimes it can be tough to figure out what's working for you and what isn't. Although there are many reasons the number on the scale might not be budging, there are some subtle ways you could be sabotaging your weight loss efforts without even realizing it.

You don’t have to spend much time on social media before you’re likely to see a post about weight loss. It may be someone promoting their newest weight loss goal. Another might lament that their diet is too restrictive for them to splurge on their favorite snack.

Stress is OK in small doses — it's our body's natural response to a threat. But if you feel perpetually like Andie trying to get Miranda's twins the unreleased Harry Potter novel in The Devil Wears Prada, it can have negative consequences on your body and mind. One of these side effects: weight gain. We talked to Dr. Charlie Seltzer, a physician board-certified in obesity medicine, to see how, exactly, stress can make you gain weight.

For some, the keto diet may seem like a dream — eat as much bacon and guacamole as you desire? Yes please!— but there is a lot to consider before jumping on board, like all of the foods you will be forced to give up.

While non-invasive procedures are increasing in popularity, CoolSculpting isn’t exactly a magic weight loss elixir—but it can be effective for the right type of person.

Coffee has a whole host of health benefits: living longer, decreased risk of heart disease and type 2 diabetes, and protecting your heart. If you drink a glass of water but then follow it with a cup of coffee, does that offset the water you just drank? We asked a doctor for answers.

When a Kardashian shares a weight loss tip, people listen. After all, Kim has been enormously successful losing the 60 pounds she gained during pregnancy; Kourtney lost 35 pounds in the five months following the birth of her youngest child and now uses her app as a platform to blog healthy living tips; and Khloé, who authored the book Strong Looks Better Naked, appears to be maintaining her 40-pound weight loss.

Yet another celeb is touting the weight-loss benefits of the ketogenic diet, with former adult film actress Jenna Jameson sharing on Instagram that she dropped 57 pounds, dropping from a 16 to a six in pants size, in less than four months, courtesy of the high-fat, low-carb diet. That's almost 15 pounds a month, which is sorta ridiculous (and not necessarily in a good way).

Weight-loss shakes have been around for decades. But today, there's something for everyone, whether you're vegan, paleo, gluten-free, lactose intolerant — or you just want anything that gets you closer to your weight-loss goal.

The thyroid, a butterfly-shaped gland at the front of the neck, might not seem like much to look at, but when it is malfunctioning, it can wreak havoc on your health. The thyroid produces thyroxin (T4) and triiodothyronine (T3) hormones that control the metabolism, respiration, temperature and other important functions of the body.

While some of their weight loss strategies are ineffective (and a bit absurd), the Kardashians do have access to the best nutritionists and fitness trainers that money can buy. To figure out which of their weight loss tips are safe and effective for people who may need to lose weight, Cosmopolitan.com asked Philadelphia-based weight-loss specialist Charlie Seltzer, MD, to assess.

A local doctor says he has the secret to helping people lose weight while eating more. The problem with many diets is you cut back on calories and you lose weight. But then as soon as you go back to eating more, you gain the weight back. Now one local weight loss doctor has a plan to stop that cycle and help people lose weight and keep it off.

Truth: We’re all guilty of sneaking a peek at our tracker a few too many times a day in hopes hitting those coveted 10,000 steps. But will those paces actually take down the number on the scale?

Congratulations to my client, Tawny Clark, who is featured in the August issue of Oxygen Magazine. The article talks about Tawny’s battle with binge eating disorder. I am very proud to be able to say I have helped her in her journey to manage this very common condition (and prepped her for the photo shoot!).

I am so happy for Tawny. She looks incredible, and more importantly, she feels incredible! As an aside, for those of you who are afraid that heavy lifting will make you bulky, does Tawny look bulky? If you are unhappy with the way you look or feel, consider moving over to a more traditional, bodybuilding style of training. If that thought is daunting, give us a call. Emily and I will be happy to get you comfortable with effective and efficient resistance training. Your bones, heart, pancreas, liver, kidneys and brain will all thank you.