Does a weight loss diet promising quick results sound too good to be true? Here’s what to know about a fad diet.

It’s easy to feel pressure to look a certain way, and a diet that promises remarkable results in a short amount of time can sound alluring. However, fad diets are not sustainable in the long term and can wreak havoc on our body’s natural systems. If it sounds too good to be true, it likely is.

Jen Hathwell, MS, RD, a registered dietitian at USC Verdugo Hills Hospital, says there are common red flags associated with fad diets — which are usually focused on weight loss.

Lose weight fast?

Be wary of any diet claiming to help shed pounds quickly. “To get a lot of weight loss in a short amount of time, you’re going to be severely restricting calories and nutrients your body needs, and that can be dangerous,” Hathwell warns.

Once those calories are added back into your diet, the weight returns as well. “Some people then start another restrictive diet, creating a cycle of weight loss and weight gain and on-and-off dieting.”

“Bad” food

Moderation is the standard advice when it comes to eating sugary and salty treats. Hathwell says to avoid diets that label certain foods as “bad” because this can perpetuate an unhealthy relationship with food.

She says attempting to completely cut out so-called “bad” foods can “lead to overeating of those foods once we do consume them and negatively affect our moods if we feel like we’re doing something wrong.”

Eliminating food groups

“Any diet that tells you to cut out major food groups — fruits, vegetables, whole grains — is something to look out for,” Hathwell says. She lists examples such as the Paleo diet, which eliminates grains, dairy and legumes, and the Ketogenic and Atkins diets, which restrict carbohydrates.

Hathwell also labels intermittent fasting, which can lead to overeating and energy loss, as a fad. “Putting your body into starvation mode affects satiety and hunger hormones and alters your metabolism.”

Why Fad Diets Don’t Work

The number one reason fad diets don’t work is they’re not sustainable. While a person may succeed in temporarily dropping pounds, they’ll gain the weight back once they start eating normally again — and repeatedly trying various fad diets can have severe physiological consequences.

“The up-and-down action of gaining and losing weight has long-term effects on our appetite,” Hathwell explains. Research shows restrictive eating habits can mess with natural hormones that tell us when we’re hungry and when we’re full.

The end result, ironically, is that a fad diet can ultimately increase a person’s appetite and cause him or her to gain weight in the long term.

By comparison, a healthy diet won’t have excessive restrictions. “A Mediterranean diet, for example, focuses on healthy fats, fish, fruits and vegetables, nuts and grains,” Hathwell says. “It’s not telling you to stop eating other foods.”

A Healthier Approach

For women trying to shed excess weight after giving birth, Hathwell urges patience because the healthiest route to weight loss is losing one to two pounds per week. She also cautions that restrictive diets may reduce breastmilk production.

“It’s all about that slow, sustainable weight loss. It feels like it might take a while, but you’ll get there.”

Hathwell shares a few recommendations for reaching and maintaining a healthy weight:

• Start by setting short-term achievable goals, like cutting out sodas for one week, rather than trying to overhaul all of your eating habits at once.
• Practice mindful eating — listen to your body’s cues that you’re full.
• Focus on eating more whole foods and less processed items.
• Aim for at least 150 minutes of moderate exercise per week.

Author: Erin Laviola