Why the Optavia diet can help you lose weight fast but is not recommended by dietitians

• The Optavia diet involves eating small pre-prepared meals, called fuelings, throughout the day.
• Optavia's fuelings can be expensive costing between $400 and $450 per month.
• Optavia's most popular plan, 5&1, involves eating low carbs, lean meats, and about 1,000 calories/day.

The Optavia diet aims for rapid weight loss centered around pre-packaged foods like soups, brownies, and shakes that the company calls "fuelings."

The most popular Optavia plan, called the "5&1," consists of eating five fuelings each day and one meal consisting of lean protein and vegetables.

"It is basically a low-carb, high protein meal plan," says Erin Holley, RD, a registered dietitian at The Ohio State University Wexner Medical Center.

Although Optavia can lead to rapid weight loss, it's not a sustainable approach to healthy eating due to the calorie restrictions and reliance on prepared foods, says Holley.

"In order for a diet to work long term, it has to be realistic," she says, adding that the Optavia diet does not match that description.

What is Optavia?

The Optavia diet was introduced in 2017. The diet encourages people to eat small portions throughout the day, centered on the pre-packaged foods that the company sells.

In addition to these fuelings, you'll eat between one and three "lean and green" meals per day. These are meals that you make and buy on your own. Each meal should have one serving of lean protein, like fish, and three servings of non-starchy vegetables, like broccoli, and two servings of healthy fats, like olive oil.

Optavia offers two plans:

• 5&1 Plan: You'll eat five fuelings and one lean and green meal. Optavia recommends this plan for people seeking to lose weight.
• Optimal Health 3&3 Plan: You'll eat three fuelings and three lean and green meals. This is recommended for sustaining weight loss.

Two other plans are available to people who have additional considerations. According to Optavia, this includes people with medical conditions like diabetes, those that exercise more than 45 minutes each day, and those over 65. If you fall into those groups you should talk to your doctor about if either plan is right for you.

• Optimal Weight 4&2&1 Plan: You'll eat four fuelings, two lean and green meals, and one healthy snack, consuming 1,100-1,300 calories each day.
• Optimal Weight 5&2&2 Plan: You'll eat five fuelings, two lean and green meals, and two healthy snacks, consuming 1,300-1,500 calories each day.

The plan also promotes working with Optavia coaches, but that may sound better on paper than in reality, says Amy Adams, RDN, founder of Backyard RD.

"These coaches do not necessarily have a background in health or nutrition," Adams says. All that's required to become a coach is purchasing an Optavia business kit, she adds.

Who makes the Optavia diet?

The diet was developed and marketed by Medifast. The company is known for weight loss plans like Optavia, Medifast, and Take Shape for Life that are built around pre-packed foods.

The multilevel marketing company previously settled a lawsuit over unsubstantiated claims about weight loss from its products. This lawsuit happened before Optavia was launched and didn't deal with Optavia.

How does the Optavia diet work?

The Optavia plan creates a calorie deficit, which encourages weight loss.

On the 5&1 plan, which Optavia recommends for weight loss, you will consume:

• 800-1,000 calories per day
• 80-100 grams of carbohydrates, making it a low-carb plan
• At least 72 grams of protein
• Less than 30% of calories from total fat, which based on the calories target would be about 27-33 grams

This can lead to rapid weight loss, but the results likely won't last, Adams says.

"Most diets that are low-carbohydrate or are very low-calorie focused tend to only show significant results short-term," she says. "In general, these diets are not sustainable, and many participants may regain the weight they lost."

Is Optavia healthy?

Overall the diet focuses too heavily on processed foods and doesn't provide enough calories or carbohydrates, says Holley.

"It's not nearly enough to fuel your body properly," she says.

The Dietary Guidelines for Americans recommends that the average adult woman consume at least 1,600 calories per day, and adult men consume at least 2,000 calories. This amount will vary depending on factors like age and activity level.

From those calories, 10%-35% should come from protein,45%-65% from carbohydrates, and 20%-35% from fat.

Moreover, losing weight too quickly can lead to hormonal imbalances, loss of muscle mass, and trigger unhealthy obsessions over food. In addition, there's no research to support the long-term success of Optavia, Holley says.

Is anything healthy about the Optavia diet?

The plan recommends eating fish twice each week, which is in line with federal recommendations. But overall, the Optavia program may not lead to good long-term health or weight management.

Does the Optavia diet cost anything?

To follow the Optavia diet, you must purchase fuelings from the company. That will cost you between $400-$450 each month. This is on top of the cost of groceries that you'd buy for making your "lean and green" meals or meals made with fresh foods.

"This program is super expensive," Adams says.

Since you need to purchase the fuelings even in the maintenance phase, you'll be spending thousands of dollars on this diet long-term. If you're able and willing to spend money on eating healthier, there are better ways, says Adams.

"Save money and speak to a registered dietician who can tailor a plan to fit your needs and ensure you have a healthy relationship with food," she says.

Alternatives and other considerations

The Optavia diet has captured the public's imagination because of celebrity success stories like "Cake Boss" star Buddy Valastro, who said he lost weight on the plan. Although these stories boast rapid weight loss on the plan, the diet won't transform your health overnight Holley says.

"Diet plans are not a magic pill," Holley says.

Rather than spending on a specific diet, she recommends following the tried and true methods of reaching and maintaining a healthy weight. Eat a diet rich in whole foods, including fruits and vegetables, whole grains, lean protein, and healthy fats.

"Stick to the basics: Move your body, eat a well-balanced diet, find ways to reduce or manage stress, have fun and live your life," she says.

Insider's takeaway

It's natural to wonder if a popular diet can help you lose weight and improve your health. Yet, the best approach to sustainable weight loss is by incorporating small, repeatable changes into your routine that you can stick with long-term.

"A good rule of thumb would be to stay away from any diet that promises 'quick fixes,'" Adams says.

The Optavia Diet relies on severe calorie restriction and processed foods, which are expensive to purchase. That makes it restrictive and unrealistic, says Holley.

Instead of signing up for Optavia, consider meeting with a dietician who can work on your specific health and wellness needs, creating a plan that you can follow for a lifetime, not just a few weeks. Start by making small changes like incorporating fruits and vegetables into your meals, or reducing your intake of sugary snacks. Those changes will pay off in the long term.

"Fad diets, cleanses, detoxes, fasts, supplement pills, etc. are not necessary to lose weight or be healthy," Holley says. "Just say no to fad diets."