Jillian Michaels says the key to losing 'the last 10 lbs' is to eat more, with no more than 500-calorie deficit a day, but experts say it's an imperfect method

• Jillian Michaels told her followers to follow a 500-calorie deficit in order to lose "vanity pounds."
• "Vanity pounds" refers to small amounts of fat on an already healthy and lean person.
• Registered dietitians told Insider the method is arbitrary, and may not be healthy for everyone.

Celebrity trainer Jillian Michaels recently shared some nuanced weight loss advice in an Instagram post.

Michaels said any followers who are looking to lose "vanity pounds" - or "the last 10 pounds" in a weight loss program - should increase their calorie intake.

She said losing weight requires eating fewer calories and burning more, but on the final stretch dieters should maintain no less than a 500-calorie-per-day deficit.

"If I'm working out and I'm burning 500 calories a day then I really don't want to eat less than 1,700 [calories]," Michaels said. "It's very different than eating to lose 30, 40, 50, or 100 pounds. You're body wants to drop that weight, it does not want to drop vanity pounds."

According to Michaels, this strategy gives the body just enough calories so that the metabolism will naturally burn the fat, while consuming too few calories will bring the metabolism to a stall and prevent weight loss.

Experts told Insider Michaels' advice falls in line with conventional weight loss strategy, but 500 calories is an arbitrary number, and since there is no one-size-fits-all approach to weight loss this may not be healthy for everyone.

The calorie deficit could be even smaller, one dietitian said

Alix Turoff, a registered dietitian and certified physical therapist, believes that Michaels' advice is "usually the standard rule of thumb."

Plenty of dietitians have recommended similar strategies, too.

Kimberly Lummus of the Texas Dietetic Association, for example, told Everydayhealth.com that an effective way to lose weight is to create a calorie deficit, but if your calorie intake dips too low then your body could go into "starvation mode" and the body will burn calories as slowly as possible to preserve energy.

But Turoff believes that Michaels' recommendation of a maximum 500-calorie deficit may actually be too large, and those looking to lose weight should eat more than Michaels recommends.

"You can definitely create a smaller deficit, 250-300 calories per day, especially as you get closer to your goal weight because that usually means you've already cut your calories quite a bit and you probably don't have as much room to cut," Turoff said.

"So I would say whether you're trying to lose the first or the last 10 lbs, the advice wouldn't really change. People who are trying to 'lose the last 10 lbs' usually have been dieting for a more extended period of time and as a result, it gets harder to lose weight."

Another dietitian says Michaels is not considering the individual circumstances of her followers

Registered dietitian Bonnie Taub-Dix, creator of BetterThanDieting.com, says that Michaels' method may be effective with weight loss, but it doesn't necessarily feed into the betterment of anyone's health.

"She's speaking to a very specific audience, because it really focuses on the vanity of what you look like as opposed to what you feel like in your state of health," Taub-Dix told Insider.

Taub-Dix also believes that the method may not work for everyone based on their genetics, natural physiology, and food sensitivities. Medical conditions like hyperthyroidism or inflammation can make weight loss in general less attainable, despite monitoring caloric intake.

"It doesn't necessarily work like that for everyone," Taub-Dix said. "This is basically a very simplified mathematic equation that doesn't very simply fit into people's everyday lives."