Chances are, you’ve heard some buzz about the popular Ideal Protein diet — perhaps some good reviews and some not-so-good. Here’s the lowdown. According to Business Wire, Tran Tien Chanh, MD, PhD, and cofounder Olivier Benloulou, an entrepreneur without a medical background, founded Ideal Protein back in 2004. Early in his career, Dr. Chanh worked in Paris as a general practitioner and sports physician, and he later took an interest in weight loss and its potential role in treating health conditions like high blood pressure, the company website states. The primary goal of the diet is to lose weight to improve overall health. To do so, the Ideal Protein creators encourage following a ketogenic-style three-phase protocol. The ketogenic diet is a popular high-fat, moderate-protein, very-low-carb diet originally designed to help hard-to-treat patients with epilepsy and now commonly used for fast weight loss, as an article in StatPearls notes. In Ideal Protein, though, keto has a different meaning. (More on this later.) “The [Ideal Protein] protocol focuses on cutting out sugar and carbs, limiting fats, and getting the ideal amount of protein,” explains Vicki Shanta Retelny, RDN, the Chicago-based creator of the podcast Nourishing Notes. The first phase is where all the weight loss is supposed to happen, while the other two focus on maintenance. Proponents of Ideal Protein encourage use of the plan’s branded packaged foods and supplements, too. The diet has become popular as more people have become curious about ketogenic styles of eating. In this detailed guide, discover what you need to know about Ideal Protein and whether the diet is all it’s cracked up to be. Per Mayo Clinic, staying in ketosis can help with weight loss, but it often takes two or three weeks for the body to start using fat as fuel. Here, discover more about the phases of the Ideal Protein diet.

Phase 1

This part of the diet focuses on weight loss. In this phase, you’ll extremely limit carbohydrates and sugar so that your body enters ketosis and starts burning fat as fuel (proponents of Ideal Protein say it also helps reset your metabolism). You stay in this phase as long as it takes for you to reach your desired weight. Also in this phase you’ll also start eating Ideal Protein packaged foods (and supplements) from the plan, and you’ll be connected with a health coach who’s there to help you stay motivated on the program, and later to help you reintroduce carbohydrates and maintain your goal weight. (Note that this coach is not a medical professional.)

Phase 2

In this second “stabilization” phase, your coach will have you start reintroducing carbohydrates, and help you find the right balance of carbohydrates, fat, and protein — aka macronutrients — to maintain this new weight (they call it your “macro code”). This macro code, they say, is specific to you.

Phase 3

The final “maintenance” phase has you continue to use the macro code that you established in phase 2 so that you can stay at your desired weight. Simply put, Ideal Protein is high in protein, whereas keto is very high in fat, per the Cleveland Clinic. In keto, 60 percent of your calories come from fat. “Since protein fuels muscle mass,” says Retelny, “the diet is built around the notion that eating the ideal amount of protein every day will adequately fuel muscle mass and stimulate a metabolic boost (ketosis) leading to weight loss.” The Ideal Protein diet encourages participants to buy prepackaged foods, whereas the ketogenic diet emphasizes real, whole foods, and there is no single go-to commercial company that provides your food, the Cleveland Clinic states.

Paleo Diet vs. Ideal Protein Diet

The paleo diet may sound similar to the Ideal Protein diet, because the paleo diet is a high protein, moderate fat, and relatively low-carbohydrate plan, according to Harvard T.H. Chan School of Public Health. On the paleo diet, people avoid foods that became popular within the past 10,000 years, including grains and refined sugar. Still, there are some key differences — namely, notes the Mayo Clinic, the paleo diet suggests cutting out highly processed foods (if a caveman wouldn’t recognize it, you don’t eat it on the paleo diet), while the Ideal Protein diet includes lots of packaged foods (for example, on their website they feature a “Ready-to-Serve Caramel Coffee Shake”). Also, fruits and vegetables are permitted on the paleo diet, whereas fruits and many vegetables are banned in the first phase of the Ideal Protein diet.

The Diet May Encourage Certain Healthy Eating Habits

Experts often discuss the drawbacks of consuming too many treats and sugary drinks, but it can be tough to eliminate these foods entirely. On strict protocols like Ideal Protein, you have to, though. “The benefits are that people cut out sugary foods and beverages and think more about the quality of the calories they are eating,” says Retelny. “It forces those on the diet to be selective about carbohydrate choices, which can be beneficial in treating and preventing prediabetes and type 2 diabetes, as well as aid in weight loss,” Retelny adds. The Mayo Clinic echoes those possible perks: The right kind of carbohydrates, like those in vegetables, can help prevent diseases, while the carbohydrates in desserts provide little nutrition and can be detrimental to your health, the group notes.

High-Protein Diets Can Help You Lose Weight

If losing weight is your ultimate goal, that’s a true perk of the diet. “Research shows that high protein diets are effective in producing weight loss; however, more studies are needed when following the diet for over 12 months to investigate pros and cons,” says Sue-Ellen Anderson-Haynes, RDN, CDCES, the Boston-based founder of 360 Girls and Women, and a national media spokesperson for the Academy of Nutrition and Dietetics. She points to a review published in the September 2020 Journal of Obesity and Metabolic Syndrome that suggests a high-protein diet produces weight loss effects and is a safe way to shed pounds. And yet, whether upping protein can really reset your metabolism, as the company claims, is debatable.

A Health Coach May Help You Stay on Track

Trying to lose weight alone can be a daunting task. That’s why Anderson-Haynes says a health coach, which is part of the Ideal Protein plan, can be beneficial. A study published in August 2022 in JAMA Network Open found that people who had support on a commercial weight loss program shed significantly more pounds than those who took a do-it-yourself weight loss approach. Retelny agrees that support on a keto style of eating such as Ideal Protein is essential. “The accountability of having a coach can positively impact health and help with weight loss and maintenance,” says Retelny. (And on the Ideal Protein program, a health coach is mandatory. That said, you may want to opt for someone with credentials such as an RDN, as the Ideal Protein health coaches don’t necessarily have professional nutrition training.)

Bringing Back Banned Fruits and Vegetables in Phase 2 Is a Good Thing

While registered dietitians don’t love the lack of vegetables, fruits, legumes, and nuts in phase 1 of the diet, the fact that they potentially make a comeback in phase 2 is a positive. “Incorporating carbs and healthy fats during the second phase is promising, adds Anderson-Haynes. And according to Harvard T.H. Chan School of Public Health, a diet full of varied fruits and vegetables can decrease your blood pressure, reduce your odds of heart disease and stroke, and prevent certain cancers, among other possible health benefits.

A Long Period of Dieting Usually Isn’t Sustainable

Strict diets can help with weight loss, but the results may not last. “In terms of low-carb diets for weight loss, studies reveal that it produces short-term weight loss; more long-term studies are needed to account for its effectiveness,” says Anderson-Haynes. For example, one review, published in the Medical Clinics of North America in January 2018, noted that while a person can lose weight through a number of methods, keeping the weight off is the real challenge, and that a typical cycle is weight loss, weight plateau, and weight regain.

People May Unnecessarily Restrict Healthy Foods

Certain foods contain important nutrients (hello, produce!), but may be too high in carbohydrates for a low-carb diet. “A low-carb diet requires restriction of fruits, whole grains like rice and pasta, and starchy vegetables like sweet potatoes and corn, all of which are packed with important nutrients like antioxidants, fiber, and micronutrients like magnesium,” says Anderson-Haynes. And although protein is encouraged on Ideal Protein, many plant-based proteins are discouraged. Take plant sources like legumes, for example, which are associated with a healthy metabolism, past research notes. Those nutrient-packed foods are on the do-not-eat list for Ideal Protein.

You Need to Buy Their Packaged Products

An integral part of the Ideal Protein plan is the company’s packaged foods. For people who may be trying to limit their packaged and processed food consumption, this can be a real problem. Also, packaged food purchases will spike your grocery bill (more on that later).

Ultraprocessed Foods May Be Unhealthy in the Long Run

Indeed, many health professionals encourage a shift away from highly processed packaged foods, which are a key part of the Ideal Protein diet. A review published in the January 2020 Nutrition noted that if you’re trying to lose weight for better health, good, high-quality foods such as whole fruits and vegetables are key. Another study, in the May 2019 BMJ, found that a diet high in ultraprocessed foods, which are involved in the Ideal Protein diet, was associated with an increased risk of cardiovascular disease. A study in the February 2018 BMJ linked these processed foods to an increased breast cancer risk.

Supplements Are Required on the Diet

Another component of the Ideal Protein diet is their branded supplements. They include a multivitamin, a calcium-magnesium supplement, an omega-3 supplement, and a potassium supplement, according to an Ideal Protein affiliate. The U.S. Food and Drug Administration (FDA) does not regulate supplements the same way they regulate conventional medication, and manufacturers can produce and market a supplement without notifying the FDA. The National Institutes of Health recommends a cautious view of supplements. An editorial published in June 2022 in JAMA Internal Medicine stated that there is little evidence that vitamin and mineral supplements do anything to prevent cancer, cardiovascular disease, or premature death. The author concluded, “In the face of such underwhelming benefits, what explains the number of people who regularly consume these unnecessary supplements?”

Too Much Protein May Not Be Healthy for Some People

“Excess protein carries risk, especially for those with liver and kidney conditions,” says Anderson-Haynes. A review in the August 2020 Journal of the American Society of Nephrology found that high-protein diets affected how the kidneys function in people with or without any preexisting kidney issues. Protein type matters, too. On the Ideal Protein diet, protein sources include their packaged items like Chicken Chowder, Thai Pork Soup, and Peanut Butter Bar, as well as approved proteins like flank steak, skinless breast, and salmon. “Protein can also affect how the body uses insulin — a study in the American Diabetes Association’s journal Diabetes Care reported that diets high in animal protein can increase diabetes risk,” says Anderson-Haynes.

Veganism Isn’t Possible on the Diet

As the company states on their website, Ideal Protein doesn’t allow for veganism (though vegetarianism is allowed). “This is a major limitation, given the environmental climate, rising cost of food — specifically, animal protein foods — and evidence in research pointing to a plant-forward eating style to improve health and longevity,” says Anderson-Haynes. Veganism specifically may be helpful for weight. A review published in the September 2022 Obesity Reviews found that a vegan diet may lower body weight, and reduce a person’s A1C, which is a marker for diabetes, and LDL “bad” cholesterol. The review didn’t find a connection between going vegan and lowering blood pressure or raising “good” HDL cholesterol, though.

There’s Not Enough Research on Ideal Protein

There are no studies showing that this specific plan can help people lose weight and keep it off to improve their health. The company claims that weight loss is healthcare, but whether weight loss through Ideal Protein directly helps people become healthier is unproven. Beyond that, the Cleveland Clinic notes there isn’t enough evidence to show the ketogenic diet more broadly is safe over a period of 20 to 30 years. Ideal Protein is a type of keto diet, and these approaches may promote weight loss and certain health benefits. Nonetheless, health experts agree that more studies are needed. A review in the May 2019 Nutrients concluded that the ketogenic diet can be an effective diet for people with obesity or type 2 diabetes, but that the diet should be tailored to the individual’s needs. Notably, this research included the popular version of the ketogenic diet, not the style in the Ideal Protein protocol. The main goal of Ideal Protein is to help you lose weight, and weight loss is associated with several health benefits. For example, a review published in the Lancet in January 2022 concluded that to treat type 2 diabetes, medical professionals should first focus on obesity and then blood glucose, or sugar, control. Weight loss plays a key role in lowering A1C, or two- to three-month average blood sugar levels. A1C is a key measure of diabetes management quality. Another study, in the August 2017 European Heart Journal, found that overweight or obesity puts a person at risk for heart disease, even if he or she is otherwise healthy. “[Ideal Protein is] marketed as a medically supervised weight loss program,” says Retelny. Whether it’s possible for people to keep the weight off is the real question. “It’s predicated on the notion that the body burns fat when in a state of ketosis — and this can be maintained even after substantial weight loss,” says Retelny. Still, she says that research does not support this. “After a year, people typically regain the weight they’ve lost, whether the plan was low-fat, low-carb, high-protein, or a combination,” says Retelny. For example, a study in the April 2020 BMJ found that people were able to lose weight and improve their blood pressure on both a low-carbohydrate diet and a low-fat diet, but after a year, these benefits disappeared. That said, the registered dietitian-nutritionists we interviewed cited several downsides of the diet, from unsustainability to lack of scientific support. The diet also calls for eating pricey branded processed foods, which aren’t always healthy, and taking supplements that don’t have proven health benefits. In a nutshell, they said, Ideal Protein isn’t the healthiest way to lose weight. Another cost to consider are the consultation fees. These will depend on your location, Ideal Protein notes. For example, a Central Texas affiliate charges $195 for one consultation.

What to Eat

Consider the following lists as nonexhaustive. In other words, you can eat foods not listed here, too. Seafood

AnchoviesSalmonPikeCodTunaRed snapperShrimpCrabSquidLobster

Beef

Flank steakRump steakFilet mignonSirloin

Veal

BreastTenderloinShoulderRib

Poultry

EggsChicken (skinless)Turkey

Pork

Lean hamTenderloin

Other Protein

Wild gamePlain tofu

Raw Vegetables and Lettuces in Unlimited Amounts

ArugulaMushroomsSpinachBok ChoyLettuceEndiveCelery

Select Vegetables — Maximum 4 Cups per Day

Bell peppersBroccoliChardZucchiniAsparagusFennelYellow summer squashRadish

Occasional Vegetables — Maximum 4 Cups per Week

Brussels sproutsGreen beansEggplantHearts of palmJicamaLeeksRutabagaSnow peasSpaghetti squashTomatilloTomatoes

What to Avoid

Pasta (other than Ideal Protein pasta, which is high in protein)RiceLegumesBreadCerealFruitFruit juiceSodaCandy, chocolate bars, chipsAlcoholVegetable juiceVegetables not included in the Unlimited, Select, or Occasional CategorySweet peasCornCheeseDairy (with the exception of 1 oz of milk or half-and-half in coffee or tea only)Nuts

Day 1

Breakfast Ideal Protein Cheese Omelet Lunch Ideal Protein Mac & Cheese, plus 2 cups approved vegetables Dinner 4–6 oz salmon, plus 2 cups approved vegetables Snack Ideal Protein Vanilla Crispy Square

Day 2

Breakfast Ideal Protein Maple Oatmeal Lunch Ideal Protein Mushroom Parmesan Risotto, plus 2 cups approved vegetables Dinner 4–6 oz chicken breast, plus 2 cups approved vegetables Snack Ideal Protein Lemon Wafers

Day 3

Breakfast Ideal Protein Chocolate Chip Pancakes Lunch Ideal Protein Vegetable Bolognese Spaghetti, plus 2 cups approved vegetables Dinner 4–6 oz flank steak, plus 2 cups approved vegetables Snack Ideal Protein Dill Pickle Zippers

Day 4

Breakfast Ideal Protein Crispy Cereal Lunch Ideal Protein Chicken Chowder Soup, plus 2 cups approved vegetables Dinner 4–6 oz veal tenderloin, plus 2 cups approved vegetables Snack Ideal Protein Pizza Curls

Day 5

Breakfast Ideal Protein Cheese Omelet Lunch Ideal Protein Veggie Meatless Patty, plus 2 cups approved vegetables Dinner 4–6 oz cod, plus 2 cups approved vegetables Snack Ideal Protein Nacho Cheese Dorados

Day 6

Breakfast Ideal Protein Maple Oatmeal Lunch Ideal Protein Mac & Cheese, plus 2 cups approved vegetables Dinner 4–6 oz lean ham, plus 2 cups approved vegetables Snack Ideal Protein Trail Mix

Day 7

Breakfast Ideal Protein Chocolate Chip Pancakes Lunch Ideal Protein Mushroom Parmesan Risotto, plus 2 cups approved vegetables Dinner 4–6 oz sirloin, plus 2 cups approved vegetables Snack Ideal Protein Apple Cinnamon Puffs Think about it as your own on-the-go nutrition coach. This app crunches the information on food labels to help you discern if the product is really healthy (or if all those claims on the package are just hot air). Each food gets a letter grade (A, B, C, etc.) so you’ll easily see if it’s nutritious. Obesity.org The Obesity Society is an organization for professionals looking to help end obesity, and on their site you can also find the latest research about obesity and weight loss.

Best Website for Finding an RDN

Eatright.org Need help finding an accredited registered dietitian-nutritionist? Eatright.org is your place to go — it’s the site run by the Academy of Nutrition and Dietetics, so you know they’ll help you connect with the real deal.

Best Website for Healthy, Lean Protein Recipes

MyPlate.gov You know the site for their “My Plate” suggested way of eating, but you can also find healthy low-cost recipes, many featuring lean protein and lots of vegetables.

Best App

My Macros+ If you’re trying to keep track of the protein you’re eating (as well as carbohydrates and fat), then consider downloading this app to help you do just that (plus, the app has a huge nutrition database, a barcode scanner, and creates useful charts and graphs). “It seems counterintuitive, but as a dietitian, I don’t like ‘diets’ — especially strict plans that cut out or demonize whole food groups,” says Retelny. “Balancing what you eat with good-quality carbohydrates, protein, and fat is essential to maintaining overall health,” she adds. Anderson-Haynes concurs. “Any eating style or diet that is not balanced and greatly restricts a macronutrient until the person reaches their goal weight can carry health consequences,” she says. “Due to the nature of the Ideal Protein diet, I would not recommend it for the general public.” If you do lose weight on the plan, Retelny says it isn’t smooth sailing after that. “The Ideal Protein diet may work in the short term with calorie restriction, but over the long term, diets that are super restrictive are not sustainable, and people gain weight back and more,” Retelny says. One study found that repeated diet attempts in general actually cause people to store more body fat than if they hadn’t “yo-yoed.” While the Ideal Protein diet does encourage weight loss, which may be beneficial for the health of some people, it might not be worth signing up for. “My recommendation is to skip diets, in general, and pay attention to red flags, like phases — which demand that you cut out or extremely limit whole food groups — extreme calorie restriction, gimmicky claims, and expensive shakes, bars and supplements,” says Retelny.