9 diet fads to try (or skip completely) in the new year

Diet trends – what works and what doesn't

Does the keto diet allow unlimited steak? Is all vegan food healthy? With so many diet plans to choose from, I understand why many patients have a tough time finding an eating plan that works. To help simplify the confusion, click on the nine diet trends represented here – and we'll discuss the potential benefits and drawbacks of each.

• 1. Intermittent fasting

  1. Intermittent fasting

  The basics: Intermittent fasters focus on when – not what – they eat, alternating periods of eating and fasting on a regular schedule. Some people only eat within a six- or eight-hour window each day, while others choose to eat only one meal a few days each week. Drinking water is encouraged at all times to ensure people stay hydrated. (Many religions also incorporate various fasting rituals.)

  The benefits: Flexibility is a major advantage; you can choose the schedule you follow, and there are no food restrictions – although processed foods should be limited. Some studies have shown fasting can improve health conditions such as obesity, diabetes, heart disease, cancer, and neurological disorders.

  Cause for concern: This plan doesn’t work well for people who need to eat at regular intervals, such as people who are breastfeeding or taking medication such as insulin that requires regular food intake. For some, fasting can also lead to overeating, undereating, or irritability.

  The bottom line: If you’ve had an eating disorder or are at risk of developing one, this is not the plan for you; it can too easily lead to binging and starving or over-restricting food intake. But if you respond well to structure and have a healthy relationship with food, intermittent fasting could help you lose weight and lower your risk of a chronic disease.

• 2. Sirtfood Diet

  2. Sirtfood diet

  The basics: The idea behind the Sirtfood Diet, a newer eating pattern quickly gaining popularity, is that “sirtfoods” – foods high in polyphenols, beneficial compounds found in plants – can boost metabolism and mood to help people lose weight and increase energy. Sirtfoods (and beverages) include red wine, green tea, dark chocolate, apples, blueberries, citrus fruits, parsley, red onion, turmeric, and kale.

  The diet includes two phases you can repeat as often as you choose: one week of having one sirtfood meal and three green juices a day, followed by two weeks of having three sirtfood meals and one green juice a day.

  The benefits: The calorie restriction can lead to short-term weight loss, and many sirtfoods contain nutrients your body needs to prevent kidney disease and other chronic conditions.

  Cause for concern: The Sirtfood Diet is not well researched, and its restrictiveness can lead to weight fluctuations and metabolism changes from over- and undereating.

  The bottom line: With so little scientific evidence on the effects of the Sirtfood diet, I recommend skipping this one. However, many of the sirtfoods have recognized health benefits and should be enjoyed as part of your usual diet.

• 3. Keto diet

  3. Keto diet

  The basics: The goal of the low-carb, high-fat ketogenic, or keto, diet is to push the body into a state of ketosis – when it burns fat for fuel instead of carbohydrates. The plan recommends replacing carbohydrates with unsaturated fats, such as avocados, seeds, and nuts. However, people often end up eating a lot of saturated fats instead, such as butter, oil, cheese, and red meat.

  The benefits: The keto diet can help you lose weight and better manage Type 2 diabetes. It’s also recommended for some children with epilepsy because it can help reduce seizures by reducing inflammation in the brain.

  Cause for concern: Side effects can be severe, ranging from unintended weight gain to high cholesterol, kidney complications, or heart palpitations. Ketosis can also be dangerous for people with Type 1 diabetes, as it can cause acid buildup in the bloodstream. Because the keto diet restricts certain foods with known health benefits, such as fruit, it is not recommended as a long-term solution for anybody.

  The bottom line: If you’re considering the keto diet, talk with your doctor about ways to modify it so you don’t eat too much protein or saturated fat. A daily steak-and-egg breakfast might be permitted on this diet, but it won’t do your long-term health any favors.

• 4. Mediterranean diet

  4. Mediterranean diet

  The basics: The Mediterranean diet focuses on fruits, vegetables, beans, nuts, and seeds, along with grains, potatoes, and lean meats such as fish and some poultry. It limits sweets, red meat, and dairy products. Olive oil is the main source of fat.

  Fully embracing the lifestyle aspect of a sustainable eating plan, the Mediterranean diet also encourages regular physical activity and taking time to enjoy meals with loved ones.

  The benefits: Following this eating pattern can reduce your risk of heart disease, diabetes, Parkinson’s disease, some cancers, and cognitive decline. The wide variety of foods you’re encouraged to eat makes this plan easier to maintain.

  Cause for concern: The risk of a vitamin D deficiency is a potential drawback if you don’t supplement when you cut back dairy; you can ask your doctor to check your blood levels. And certain foods, such as fresh berries, fish, or nuts, can be difficult to find or afford – though using frozen fruits and buying nuts in bulk can help.

  The bottom line: The Mediterranean diet is one of the healthiest – and best-studied – eating patterns to follow for patients of any age or health status. You can score yourself to see how your current diet patterns match the Mediterranean diet and make adjustments as necessary on your journey to living longer and healthier.

• 5. DASH diet

  5. DASH diet

  The basics: Often recommended for patients with heart disease and hypertension (high blood pressure), the DASH diet, which stands for Dietary Approaches to Stop Hypertension, emphasizes low-sodium, high-potassium foods such as fruits and vegetables, beans and lentils, low-fat dairy products, fish, poultry, and unsalted nuts. It limits sweetened, processed, and fast foods, as well as alcohol.

  The benefits: Studies have shown that the DASH diet can lower blood pressure in just a few weeks. No food is completely off limits, so the plan is adaptable to any culture or lifestyle.

  Cause for concern: Getting too little sodium in your diet can be as unhealthy as getting too much. This isn’t a problem for most people in the U.S., but talk with your doctor if you’re concerned about low sodium levels. And be mindful about incorporating high-fiber foods into your diet if you don’t currently eat very many; take it slow to avoid bloating and diarrhea.

  The bottom line: If you are at high risk of heart failure, this plan was created for you. Your taste buds may need to adjust at first if you’re used to eating a lot of salty products. But it’s a great reason to experiment with sodium-free spices and find new flavors you enjoy.

• 6. Paleo diet

  6. Paleo diet

  The basics: Based on the hunter-gatherer era, the paleolithic, or paleo, diet eliminates food groups that weren’t readily available before industrial farming, such as grains, dairy, sugar, legumes, and processed foods. Instead, it includes vegetables, fruits, nuts, seeds, eggs, fish, and lean meats.

  The benefits: Some studies suggest the paleo diet can help prevent Type 2 diabetes, obesity, heart disease, and some cancers.

  Cause for concern: This eating plan is highly restrictive, making long-term adherence difficult. You also miss out on the health benefits of whole grains, the fiber and vitamins in legumes, and the protein and vitamins in dairy products and plant-based milk alternatives.

  The bottom line: If you’re looking to lose weight, this eating pattern could be helpful short term. Talk with your doctor about options to add the missing nutrients and vitamins to your diet.

• 7. Vegan diet

  7. Vegan diet

  The basics: A vegan diet eliminates all animal-derived products, including honey, eggs, and dairy products.

  The benefits: Vegan diets are high in fiber and low in cholesterol. They have been linked to lower inflammation – a major contributor to chronic disease and obesity. Plus, diets high in plant-based foods and low in animal-derived foods are associated with a lower risk of heart disease.

  Cause for concern: Vegans are likely to have low levels of B12, which can increase the risk of stroke as well as depression. Cooking and dining out can be more expensive and time-consuming – you may not realize how many foods contain animal products until you stop eating them. And “vegan” or “plant-based” on a product label does not necessarily mean “healthy.” Pop-tarts and Oreos are vegan, for example, but I don’t recommend eating more of them!

  The bottom line: The more plant-based foods you eat, the better your health will be. Talk with your doctor about supplements and protein alternatives to avoid nutritional deficiencies. Research shows many benefits of a vegan diet mainly focused on whole or minimally processed foods to prevent and treat chronic diseases, but giving up all animal products may be tough for many who grew up with meat and dairy as part of their culture.

• 8. Carnivore diet

  8. Carnivore diet: Not recommended

  The basics: The opposite of veganism, the carnivore diet consists only of animal-based products, such as meat, meat, and more meat – plus butter and eggs.

  The benefits: Eliminating carbs and sugar can result in weight loss, as can a protein-rich diet that keeps you feeling full longer.

  Cause for concern: Eliminating fruits and vegetables means eliminating crucial vitamins, minerals, antioxidants, and fiber that help lower your risk of disease. Red and processed meats have also been repeatedly linked to cancer.

  The bottom line: The long-term risks greatly outweigh the short-term weight-loss benefits.

• 9. Potato diet

  9. Potato diet: Not recommended

  The basics: Eat nothing but potatoes seasoned with light spices – but not butter, bacon, sour cream, and cheese, of course.

  The benefits: Potatoes are packed with nutrients, such as fiber, healthy carbs, vitamin C, and potassium. Calorie restriction can lead to short-term weight loss.

  Cause for concern: If you eliminate all but one food from your diet, you’re missing several important fats, proteins, vitamins, and minerals that your immune system, muscles, and bones need to stay healthy. Supplements can’t make up for such a large deficit.

  The bottom line: Even if you might have heard about this working for some celebrities, the long-term risks greatly outweigh the short-term weight-loss benefits.