These diets may help you lose weight. But are they the best plan to keep that resolution?

"New year, new you."

At least, that's what we all hear each time the calendar flips back to January. When making those New Year's resolutions, the top most common promises we make to ourselves center around weight loss, the gym and fitness.

While there is nothing wrong with aiming for a healthier lifestyle in 2024, it's easy to fall victim to a mindset that focuses more heavily on how you look than how you feel. Fad diets, overly strict eating regimens and intense workout routines are appealing to us in the short term but can quickly lead to burnout, a loss of interest and even unhealthy habits.

In fact, a study published in the medical journal The BMJ in 2020 found that weight-loss diets are generally ineffective in the long term, with most of the weight lost by participants having been regained within one year.

The study followed 22,000 overweight or obese adults on 14 of the most popular diets including the Atkins diet, Weight Watchers, Jenny Craig, and the Mediterranean diet, for an average of six months.

At the initial six-month mark, some health parameters like weight, blood pressure, and cholesterol had improved in most participants, but these positive effects were all but gone by the 12-month mark (except for the Medditerarian diet, which showed persistent improvements in cholesterol.)

It's tempting to commit to the idea of a fast-acting diet to transform our bodies in the new year, but keeping a skeptical mind can help weed through the short-term solutions and find something that will ultimately work better for you.

Here's a little more information on some of the most popular diets you'll see flying around to start the year.

Keto

On a basic level, a ketogenic or "keto" diet centers around a low intake of carbohydrates coupled with a high intake of fat and protein. Generally, people following this diet get 70% to 80% of their daily calories from fat, about 20% from protein and about 5% from carbs.

The lack of carbs forces the body into the state of ketosis, during which fat becomes the main provider of fuel for the body and theoretically is burned to be used as energy.

While keto has been linked to weight loss, professionals have warned against the diet for those looking to improve their overall health. For starters, limiting your intake of carbs so severely leads the body to break down not only fat but muscle and tissue.

The strictness of keto can also easily lead to a diet lacking in other important sources of nutrition, like whole grains, fruits and vegetables.

"I wouldn't recommend the keto diet to anybody," Jeffrey Mechanick, medical director at Mount Sinai Heart's Marie-Josée and Henry R. Kravis Center for Clinical Cardiovascular Health, previously told USA TODAY.

"In theory, the keto diet basically mimics starvation," Mechanick said. "If you don't eat carbohydrates but you eat an excessive amount of fat and protein, you're still going to waste tissue. Tissue is still going to burn off."

Mediterranean Diet

The Mediterranean diet has received accolades as one of the most successful diet plans out there.

It focuses on heart-healthy foods most often eaten by people in the Mediterranean like plants, legumes, nuts, wheat, fruits and veggies. Instead of focusing on restriction and elimination, the Mediterranean diet focuses on healthier alternatives, like replacing butter with healthier olive oil and red meat with fish and poultry.

Because this diet focuses more on overall health than weight loss, it doesn't provide straightforward guidelines about portion sizes, how often to eat and other directives often included in similar regimens. Because of this, people hoping to make this diet work need to commit to a complete lifestyle change long term to see results.

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Fasting diets

Intermittent fasting has gained widespread popularity recently, getting the attention of social media influencers, average people and doctors alike.

As previously reported by USA TODAY, intermittent fasting is a diet plan focused not on what you eat but when you eat it. It relies on set periods of fasting and eating happening in a designated period of time.

Some of the benefits include a reduced calorie intake and more flexibility with types of food, leading to a less restricted mindset around food.

"Intermittent fasting may be worth considering for both health and weight loss goals, but it's not a magic solution," Mary Sabat, a registered dietitian nutritionist and owner of BodyDesigns, previously told USA TODAY.

"If practiced consistently and combined with a balanced diet and regular physical activity, it may contribute to certain health improvements. However, individual results can vary, and it's important to approach it as part of an overall healthy lifestyle."

Paleo diet

Paleo is another low-carb diet that focuses mostly on protein, vegetables and fruit. The name is derived from the Paleolithic era in history and operates on the premise that those following it should eat like the hunter-gatherers of 2.6 million years ago.

By cutting out grains, dairy, legumes and refined and processed foods, dieters seek to emulate the more "simple" foods our ancient ancestors once ate and focus on "whole, unprocessed" foods like vegetables, nuts, seeds, and meat.

Nutrition consultant and registered dietitian Jen Messer previously told USA TODAY that "Advocates of the paleo diet believe eating this way can lead to weight loss, improved health and a reduced risk of today’s most common chronic diseases," though she said, "scientific evidence does not back up these health claims."

While the paleo diet can help promote the inclusion of healthy foods containing potassium, antioxidants and other important nutrients and discourage reliance on processed foods, it can also result in eating habits lacking in things like calcium and vitamin D.

This can lead to vitamin deficiencies, increased risk of osteoporosis and bone fractures, low blood sugar, kidney stones, constipation, heart disease and disordered eating.

Atkins diet

Another low-carb diet option, Atkins focuses on net carbs instead of total carbs consumed and now comes in two versions: Atkins 20 and Atkins 40.

As previously reported by USA TODAY, the classic diet has four phases based on increasing carb intake periodically: the first phase calls for 0 to 25 grams of carbs per day and the final phase entails 80 to 100 grams of carbs daily.

Unlike other low-carb diets, Atkins also considers fiber and sugars when calculating intake, subtracting the number of carbs you record as having eaten based on other contents of the food (if something you want to eat has 10 grams of carbs, but 3 grams of fiber and 1 gram of sugar, then your net carbs would be 6 grams.)

Atkins also offers pre-packed foods available for purchase through their program, meaning you can pay to receive prepared meals that align with your diet instead of cooking them for yourself.

As with other low-carb diets on this list, the Atkins diet can easily lead to nutritional and vitamin deficiencies due to heavy restrictions put on certain kinds of foods. It also runs the risk of causing disordered eating, worsening kidney issues and having a low rate of long-term success.

Dry January: What are the Dry January rules? What to know if you're swearing off alcohol in 2024.

WW, Noom and other diet apps

Apps are the most modern and perhaps one of the most popular solutions to dieting and weight loss. From the original Weight Watchers (now known as just WW) to the newer Noom, there are apps for weight loss, "fitness," "lifestyle changes" and everything in between.

While we may see them as an easier means of integrating dietary awareness into our daily lives, the apps can often mislead us, as they are not generally run by qualified medical professionals.

“A lot of apps I've seen will recommend as low as 1,200 calories per day, sometimes 1,500 calories,”  Jessica DeGore, RD, a Pittsburgh-based registered dietitian previously told USA TODAY'S Reviewed team. “We recommend 1,200 calories for toddlers, so I would never recommend that for a grown adult.”

Logging your calories and exercise can help with mindfulness and intentional eating but can also lead to disordered eating and unhealthy obsession.

“Whenever we put a negative label on something or put it on a shelf, we tend to crave it more,” DeGore previously said. “And that kind of makes us a little crazy and food-obsessed, which I would not consider healthy behaviors.”

This article originally appeared on USA TODAY: The best diet and weight loss plans for 2024 come with pros and cons