What if your patient’s fad diet actually works?

Fad diets are notorious for promoting unhealthy weight loss. In a world where obesity is a top public health concern, the definition of “unhealthy” when it comes to dieting and weight loss is complex. If a diet plan reduces body fat (along with blood pressure, cholesterol, and blood sugar levels), where is the boundary between healthy and unhealthy? 

Here are some pointers to consider when evaluating your patients’ weight loss plans, and practical tips to be the voice of reason in the confusing world of dieting.

What is a fad diet?

The line between certain fad diets and medical weight loss plans isn’t as clearly defined as you might think. 

However, these characteristics aren’t that far off from physician-supervised options touted by the Obesity Action Coalition.^[] Programs like OPTIFAST (from Nestle) and OPTAVIA (from Medifast) require the purchase of branded meal replacements (sometimes covered by insurance) and rely on severe calorie restrictions to achieve results.

These programs may be paired with FDA-approved obesity prescriptions, like orlistat or phentermine. Although these medications are taken under medical supervision, patients still face risks.

While both fad diets and medical weight loss programs are nothing new, social media has brought extreme weight loss tactics to a wider audience. It’s not difficult to find a diverse range of weight loss advice online. From eating dozens of bananas a day to injecting the drug Ozempic when you don’t have diabetes, over-the-top advice is easy to come by.

It’s becoming increasingly important for astute clinicians to spot vulnerable patients and effectively intervene, bringing sound advice back to the conversation.

Dieting vs. disordered eating

Patients need an individual approach to weight loss, with consideration for their unique medical history, mental health, and social influences. Anyone can fall prey to the lofty promises and “fast results” of dieting, but each person’s underlying reasons for wanting to lose weight, and their relationship with food and health, may differ. 

For example, a relatively healthy patient with superficial motivations isn’t the same as a morbidly obese patient trying to avoid bariatric surgery. 

From this vantage point, they’re more likely to make healthy changes and avoid self-harm in the name of weight loss.

Clinicians can also help by screening for dangerous behaviors (like binging and purging) and signs of malnutrition, including hair loss and anemia.^[] Providing additional resources with referrals to a registered dietitian or psychotherapist can help treat patients who exhibit signs of disordered eating.

Avoiding the dreaded yo-yo

Perhaps the biggest problem with rapid weight loss programs across the board is their lack of sustainability. For instance, studies show that liquid diets produce weight loss, but the benefits often dissipate after the reintroduction of solid food. In addition, weight loss that isn’t paired with sufficient protein or resistance training inevitably leads to significant muscle loss. 

As a result, these dieters become thinner, but experience reductions in basal metabolic rate that favor fat regain. When the cycle is repeated, it becomes harder to see the same results on a strict diet that seemed to work well in the past, setting patients up for failure and frustration.

But that’s not to say rapid weight loss is always contraindicated. 

Preservation of muscle mass is critical, especially with fast weight loss. Studies show that weight reduction primarily comes from body fat, but muscle or lean mass loss typically accounts for between 20% to 40% of total weight loss.^[] Although there’s no one-size-fits-all dietary approach, most people (particularly older adults) benefit from protein intakes above the normal recommended level when cutting calories to preserve muscle and metabolism. Strength training and other forms of exercise can also help minimize reductions in lean mass.

After significant weight loss, patients should be encouraged to participate in support groups and ongoing monitoring—through their physician or self-weight tracking—for accountability. An emphasis on the reintroduction of nutrient-dense, low-calorie foods, like fruits and vegetables, should be encouraged, along with a physically active lifestyle when possible.