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The Most Effective Weight Loss Diets, According to Experts

These eating plans will help you lose weight and keep it off for good.
FACT CHECKED BY Alek Korab

If you want to lose weight, but have no idea what approach to take, there are a number of diets claiming you'll get the outcome you want by following their way of eating. But as a registered dietitian, I know dieting isn't a one-size-fits-all kind of deal. While others may have success with a specific eating plan, your results could wind up being completely different. Read on to learn about 10 of the most effective weight loss diets, why they are effective, and who they work best for—and to ensure your health and the health of others, don't miss these 19 Ways You're Ruining Your Body, Say Health Experts.

Ketogenic Diet

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Although the ketogenic diet (AKA keto diet) was originally created for individuals with epilepsy, nowadays it's commonly used for weight loss. The diet focuses on high fat intake, moderate protein, and low carbohydrates. You typically consume around 55% to 60% of your daily calories from fat, 30% to 35% from protein, and 5% to 10% from carbohydrates. 

The purpose of eating high fat with low carbs is to get into a state of ketosis, which is when your body begins to utilize stored fat as energy instead of glucose. So with the decrease in fat storage, you're likely to see a decrease in weight. Research also indicates your appetite may be more suppressed following the keto diet due to the slow digestion rates of fat and protein as well as changes in hunger hormones.

This diet is ideal for anyone that is overweight or obese, but can result in weight gain if the diet is not sustained long-term. Individuals with type 2 diabetes may see improved blood sugar levels and weight loss when following the keto diet, but should work with a healthcare provider or registered dietitian in order to do so safely.

The keto diet is not suitable for those that have pancreatitis, liver or kidney failure, or fat metabolism disorders.

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Paleo Diet

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Flash back to the way our ancestors ate in the Paleolithic era—getting all of their food solely from hunting and gathering. This includes eating foods such as:

  • Fruits and vegetables
  • Nuts and seeds
  • Lean meats, especially grass-fed or wild game
  • Omega-3 rich fish
  • Oils from fruit and nuts

This also means eliminating foods that our paleo ancestors wouldn't have had access to such as grains, legumes, dairy, and processed foods.

With the decreased intake of high calorie processed foods along with the high protein lifestyle of paleo, weight loss typically occurs. Unfortunately, it may be challenging to stay committed to the restrictions of the diet and sustain the weight loss.

 Concerns have been raised regarding the high meat intake of the paleo diet and individuals diagnosed with heart and/or kidney disease. Post-menopausal women or those with bone diseases, such as osteoporosis, should also be medically supervised before going paleo due to the low levels of calcium and vitamin D.

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Intermittent Fasting

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There are several styles of intermittent fasting, but the purpose is to set aside a time frame of when you can eat and then you fast the remainder of the day. This can range from having a 12 hour eating window, down to an 8 hour window, or even full 24 hour fasts.

This fasting process can make your body go through various cellular and molecular changes, but the reason behind the weight loss is likely due to the decreased number of calories eaten over the week. Studies even found that intermittent fasting had effective weight loss results, but it was comparable to the participants who decreased their energy intake continuously by about 25% each day.

Intermittent fasting can be safe, as long as you're not undereating during your eating window and choosing nutrient-dense foods. This diet may not be right for you if you have a history of disordered eating since the fasting time frames could trigger past harmful eating patterns. Women may also not benefit from intermittent fasting as it can disrupt certain hormones.

Vegan or Plant-Based

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Although many people follow the vegan diet for ethical purposes, it can also lead to weight loss. When you eat vegan, you're eliminating all animal food sources including eggs and dairy. Instead your diet consists of plant-based foods such as vegetables, grains, nuts, and fruits.

Losing weight while going vegan may be slightly more complicated than other diets because it does not restrict macronutrients or calories. It's also easy to turn to processed vegan foods that can be high in sugar, fat, and sodium which will prevent the scale from moving down. In order to make this diet work for weight loss, choose whole, minimally processed foods that are high in fiber and protein.

Going vegan is generally safe for anyone, but it should be planned properly. Due to the elimination of meats and animal products, you could be lacking on certain essential nutrients including calcium, iron, and vitamin B12.

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Whole30

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The Whole30 diet doesn't put itself in the category of a weight loss diet. In fact, they discourage those that follow the diet to weigh themselves and it doesn't require calorie counting, skipped meals, or carb elimination. However, the purpose of the diet is to eat whole, unprocessed foods for 30 days which often leads to a decrease in weight.

 The elimination of sugar, alcohol, and junk foods (even if they have "approved ingredients") for 30 days will likely have you consuming less calories than normal, leading to weight loss. After that point, individuals are able to reintroduce foods one by one to pinpoint food groups that they may be sensitive to.

This diet is ideal for those looking to "reset" their eating habits, which is the main purpose of Whole 30. This will require a lot of time and attention to detail in order to ensure you're eating foods with approved ingredients.

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Atkins Diet

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The Atkins diet was developed back in the 1960s by cardiologist Robert C. Atkins. It's nearly the same as the ketogenic diet, with an emphasis on low-carbohydrate, but comes with four different phases. In the introduction phase you cut back carbohydrate intake to 20 grams per day, aiming to get the majority from vegetables. As you progress closer to your goal weight, you can add 10 grams of carbs to your week but will need to cut back again if you start to gain weight.

Similar to the keto diet, the Atkins diet likely promotes weight loss due to the appetite suppressing effects of a high protein and low carb eating pattern. It will also likely put you into ketosis, depending on how many carbs you consume each day.

Before following this diet, it's important to consult with your doctor especially if you have diabetes. Those with liver or kidney disease should also completely avoid trying the Atkins diet.

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Mediterranean Diet

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The Mediterranean diet is taking a page out of the eating patterns of those in the Mediterranean, which includes high intakes of plant-based foods. Although nothing is technically off limits, this diet recommends only eating poultry, eggs, cheese, yogurt, and red meat in moderation.

Even though calories don't need to be counted, many people lose weight following the Mediterranean diet due to it's healthy fat and high vegetable content. Research even indicates it may lead to lower central weight (around your belly area) compared to a diet with reduced fat intake.

The easy-to-follow plan of the Mediterranean diet makes it an ideal option for individuals seeking sustainable weight loss. It's also been linked with reducing your risk of chronic conditions such as heart disease and diabetes.

Volumetrics

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The purpose of the volumetrics diet is to fill up on low calorie dense foods which leads to a reduction in daily calorie intake. Very low-dense foods include non starchy fruits and vegetables, nonfat milk, and broth based soups. Low dense foods include starchy fruits and veggies, grains, low-fat milk, legumes, and low-fat mixed dishes. Once you get into medium and high dense foods, portion sizes need to be considered. This includes meat, cheese, salad dressings, chips, nuts, butter, and oil.

Since this method does require analyzing and tracking foods for their caloric density, it's an ideal option for those that have the patience and time to do so. It's also generally safe for most people as long as their calorie intake isn't too low.

DASH Diet

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Although the DASH (Dietary Approaches to Stop Hypertension) was created for those dealing with high blood pressure, it has also been rated as one of the top weight loss diets by the U.S. News and World Report.

Since the DASH diet focuses on low sodium intake, people following the diet tend to steer clear of highly processed and packaged foods that use sodium as a preservative. In doing this, it reduces the intake of high fat and calorie-dense foods. 

Sodium is necessary for our muscles and nerves to work properly, but too much can impact our health negatively. If you deal with hyponatremia (low salt concentration in your blood) or are an athlete who loses a lot of salt through sweat, you should check with your doctor before following a diet that reduces sodium intake.

Flexitarian Diet

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A combination of a flexible diet and a vegetarian diet equals the flexitarian diet. The diet emphasizes eating plant-based foods, but you are allowed to eat animal products in moderation. In doing this, you're eating more nutritious and fiber-rich foods that can both improve overall health and help you lose weight.

If you don't want to go fully vegetarian or vegan, the flexitarian diet may be the right option for you. Since it doesn't limit any food groups, it can be safely done by many individuals but does require more effort to make a diet change since it's a flexible option. And now that you've got a great foundation, don't miss these additional 19 Weight Loss Foods That Really Work, Say Experts.

 

Lacey Dunn, MS, RD, LD, CPT, founder of UpliftFit Nutrition and host of the UpliftFit Nutrition podcast, functional medicine dietitian with a fiery passion for helping women feel and look their very best. People call her the "Hormone Fairy Godmother," as her one mission in life is to help women go from surviving to thriving. Dunn specializes in all things hormones, thyroid, gut, and metabolism and incorporates on-going education into her daily life. She has Master's in Nutrition from Texas Women's University, Bachelor's in Dietetics from University of Georgia, Certified Personal Trainer (NASM), Functional Medicine Nutrition Specialist (FMNS) in training, and author of The Women's Guide to Hormonal Harmony: How to Rebalance Your Hormones, Master Your Metabolism, and Become the Boss of Your Own Body.

Alek Korab
Alek Korab is Founding Editor of Body Network Read more about Alek