Top 7 Trending Diets: That Actually Work (2021)

Written by Nathan | Updated on 13 November 2021

Each year seems to bring a whole new set of trending diets for health-conscious people to choose from, so it’s no surprise that you might feel a little overwhelmed. It can be difficult for many of the latest diet trends to pin down whether they actually work or if they’re just another fad that will be forgotten in a few months. So, here are some of 2021’s trending diets that have been shown to work and have years of support behind them. 

Keto Diet (A Diet For Losing Weight Fast)

The keto diet is a low carb, high fat, high protein diet. The ketogenic diet is one of the oldest diets in the modern world, dating back to the early 20th century where it was used primarily in treating children with epilepsy [1]. Since then, it’s seen successful use both in treating other neurological conditions and in facilitating quick, noticeable weight loss [2].

The keto diet has relatively simple rules. Carbohydrates should be kept as close to a minimum while fat is consumed at high levels, leading to a change in the body’s metabolism and a shift into a state called ketosis. Or, in simpler terms, making the body utilize ketones for energy instead of carbs or glucose. 

 Carbohydrates are the body’s default energy source, so when they are depleted, insulin levels drop [3]. This will, eventually, lead to the production of another source of energy called ketones, produced when the body reaches a state called ketosis. As long as carbs are kept below the threshold, the body will remain in ketosis, which is the goal of the keto diet [3].

Ketones are created from your body’s fat reserves, which begin to deplete as a result of low insulin levels [3]. This is the big reason why many turn to keto for weight loss; it essentially forces the body to turn to its own fat reserves for fuel rather than relying on the glucose produced through the consumption of carbs [3].

There’s been a lot of research on keto’s effects in the short term, and it’s been quite promising [3]. Adherents of the keto diet can lose significant weight quickly, and it’s been shown to help prevent and treat neurological conditions like Alzheimer’s and dementia and may be beneficial for those suffering from heart disease and type 2 diabetes by improving insulin sensitivity [3].

That said, keto should be approached carefully and may not work well long term. Harvard Health Publishing says that it should be treated as a medical diet over the long term, not just as a weight-loss strategy [4]. Over long periods of time, keto dieters can become deficient in micronutrients, suffer kidney issues due to excessive fat consumption, and may experience constipation, as the keto diet is very low in dietary fiber [4].

In general, the keto diet is always trending for a reason; many people experience quick weight loss than other diets simply can’t provide, and its clear-cut rules make it relatively easy to plan around. Just be cautious when first starting out, as the keto diet can lead to dehydration and electrolyte imbalances early on [3].

Intermittent Fasting Diet

Intermittent Fasting (IF) is another popular weight loss diet that’s seen widespread approval for years now. Unlike other types of diets, Intermittent Fasting does not restrict what you eat, but when you eat. The idea is to limit meals to certain times throughout the day or the week, with the intent of reducing how many calories you can take in.

The science behind IF is similar to other diets like keto, though it follows a different process. Essentially, carbs are broken down into sugar in the body. If too much sugar is used, the excess is turned into fat and stored in the fat cells via insulin [5]. Insulin is the hormone that facilitates the absorption of sugar into fat cells, but if insulin drops, then the body will begin releasing fat to be used as energy [5]. The best way to keep insulin levels down is to simply not eat anything for a period of time, which is the idea behind IF [5].

There’s a lot of different types of intermittent fasting, and they can vary in their effects on weight loss and health gains. Here’s a few:

  • Every other day fasting: A particularly difficult regimen that requires alternating days of eating normally and eating nothing, and one that has been shown to be ineffective compared to just eating less every day [5].
  • 16:8 fasting: fasting for 16 hours, then eating how you like for the other 8.
  • Circadian rhythm fasting: A regimen designed to fit fasting into the human day/night cycle.

Research shows that intermittent fasting in the 16:8 and circadian rhythm formats can have an effect similar to keto, where fasting shifts the body’s metabolism into a different state where more ketones are produced and fewer glucose molecules [5]. Overall, intermittent fasting seems to be something the body is trained to handle, resulting in health benefits from improved metabolism to lowered blood sugar and even reduced risk for cancers [5].

From a research perspective, the most successful form of intermittent fasting has been circadian rhythm fasting [5]. For this type, dieters eat only during an early period in the day for about 8-10 hours, such as from 7 am to 3 pm [5]. In clinical studies, this resulted in lower insulin levels, reduced appetite overall, and significant improvements to metabolism [5].

One of the great advantages of intermittent fasting is that it leaves you open to decide what you eat. This means you can easily try other diets while also trying intermittent fasting. For example, if you also have blood pressure concerns, consider combining the DASH diet (described below) with intermittent fasting to get the best of both worlds. However, it’s probably best not to do that with more intensive diets like keto, which will already bring on some new physiological changes due to their unique requirements.

Intermittent fasting shouldn’t be the only change in your diet, though. It’s best paired with eating other healthy foods, such as those found in the Mediterranean diet. Additionally, don’t feel like you need to stick to the exact same schedule as everyone else; experiment with fasting and eating times and decide on what works best for you.

Mediterranean Diet (Highly Health-Conscious)

Even though it’s a little odd, there’s a good reason for a diet dating back to before Greece became one of the most popular trending diets in recent years. The Mediterranean diet is designed to center around foods traditionally eaten in that region, such as fish, fruits, vegetables, nuts, olive oil, and relatively little red meat. An advantage of Mediterranean cuisine is that it doesn’t require making any odd adjustments to when you eat, nor does it need you to drastically cut down on calories each day. You simply eat as the Mediterraneans do.

Medical research on the Mediterranean diet indicates it works so well simply because it is focused on food that is good for you at a basic level [6]. If you haven’t noticed by now, much of the advice in these diets boils down to how it is necessary to eat lots of fruit and vegetables, moderate portions of meat (with red meat at even lower levels), and to treat sugary treats and desserts as special occasions, not something to be eaten regularly. The difference in all these diets is really just how you get to that point based on what strategy works for your lifestyle. Ultimately, healthy nutrition should be the goal for any diet.

Besides weight loss, the food of the Mediterranean has been shown in research to be especially effective at preventing and treating cardiovascular diseases and seems to be effective in preventing type 2 diabetes [7]. Compared to other diets, it is among the most extensively supported by medical professionals [7].

Generally, a person following the Mediterranean diet shouldn’t expect to run into any risks or complications due to following it, though your wallet might take a hit. The type of food included in the Mediterranean cuisine can be pricey, so take that into consideration.

If you enjoy variety in your diet and don’t want to be limited to just one cuisine, consider similar cuisines from other cultures known for good health and long life, such as Japanese food.

DASH Diet

Some of the recent diet trends have been designed by medical professionals to treat certain conditions. DASH is one such example. DASH stands for “dietary approaches to stop hypertension”; it’s a diet designed to lower blood pressure by focusing on blood pressure-friendly foods and reducing salt intake. The DASH diet is designed to include lots of fruit, vegetables, legumes, seeds (like flaxseed), and low-fat dairy products [2].

The DASH diet doesn’t require any special foods; good nutrition is the only goal. Dieters simply have to stick to a diet plan that includes:

  • fruits
  • vegetables
  • nuts
  • fish
  • chicken [8]

On the other hand, dieters should limit their intake of these:

  • Salt in general to no more than 2,300mg per day
  • saturated fats
  • sugary food and drink [8]

It’s also recommended to get around 4,700mg of potassium every day, as potassium helps regulate salt intake [8].

Clinical studies have shown that DASH achieves its goals of lowering blood pressure and reducing the risk for cardiovascular disease. It does so with considerably more success than other types of diets [8]. However, DASH is not explicitly a weight-loss diet, though it has been reported to help with weight loss [8]. Its chief use is in reducing blood pressure; weight loss still requires reducing daily calorie intake [8]. Proponents of this diet stress that it is not a quick road to success; it is meant to change your eating habits to healthier ones over time [8].

If you have problems with blood pressure, DASH is definitely a diet you should consider. You may be interested in another diet that is a hybrid of DASH and the Mediterranean diet, called MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay), developed to be particularly effective in lowering the risk of neurological diseases; by as much as 53% for devoted followers [2].

Paleo Diet (Eating Like Your Ancestors)

An old hat among trending diets, the Paleo diet is well known at this point; it’s designed to mimic the eating habits of paleolithic humans who, according to the diet’s proponents, ate healthier than we do today. The Paleo diet plan includes:

  • lean meats and proteins
  • fish
  • fruits
  • vegetables
  • nuts

Any products that require sophisticated processing or stem from agricultural processes, such as whole grains, cereals, legumes, or dairy products, should be avoided, so this diet tends to be pretty sparse and simple in terms of food choices. While there are some criticisms of this diet’s veracity when it comes to its links to paleolithic humanity, health experts like those at Harvard’s School of Public Health believe it results in better eating habits and generalized health improvements [9, 10]. Paleo is high-protein, moderate fats, low in carbs (glycemic carbs are the main type to avoid), low in salt, and low in sugar [9]. Followers of this diet also get good amounts of omega-3 from fish [9].

Criticisms of Paleo mostly stem from the fact it is impossible to consume the exact same foods ancient humans did. The foods eaten back then were made from plants no longer in widespread availability, so copying them is more or less impossible [9]. Additionally, the paleolithic diet would have varied all over the world, so it’s hard to pin what exactly is Paleo or not [9]. Still, making an attempt to plan your meals like an ancient human will likely lead to better health anyway.

This is because studies have shown that, while truly mimicking your ancestor’s eating habits is impossible due to how humanity’s crops have evolved, following it as closely as possible leads to weight-loss and better bowel health, especially for sufferers of irritable bowel syndrome [9]. So, it’s definitely worth trying if you want a simpler diet plan and want to change your nutrition to something a little more natural.

Low FODMAP Diet (IBS Friendly Foods)

Suppose you’re among the 1 out 10 people in the US who suffer from irritable bowel syndrome (IBS), an intestinal disorder that can result in discomfort and pain in the abdomen. In that case, you might have already heard of the low FODMAP diet [11]. FODMAP is an acronym encompassing the types of foods that can exacerbate IBS symptoms. Here’s the breakdown of fermentable sugars that can trigger IBS:

  • Oligosaccharides: fructans and galacto-oligosaccharides (found in foods like grains, artichokes, and broccoli)
  • Disaccharides: lactose (dairy products)
  • Monosaccharides: fructose (found in fruits like apples or pears, also found in high-fructose corn syrup)
  • Polyols: sorbitol and mannitol (aka sugar alcohols, commonly found as artificial sweeteners like xylitol [11]

All of these chemicals are forms of carbohydrates, essentially sugar [12].

These chemicals are fermentable because, in people with IBS, they are improperly absorbed by the intestine, causing them to ferment and lead to bloating, gas, and excessive liquid in the intestines [11]. This can cause a lot of changes to bowel movement regularity, often leaving IBS sufferers in constant fear of encountering intestinal distress in inconvenient situations. However, the low FODMAP diet has proven to be remarkably effective in treating IBS, with most people following it reporting significant improvements to their quality of life [11].

The downside to the low FODMAP diet is that it is not intuitive what foods are good or bad, so consulting a chart, like this one from University of Virginia, is necessary when grocery shopping or eating out [12]. For example, milk is a high FODMAP food, yet cheeses are generally low FODMAP [12]. Additionally, some categories of FODMAPS can sneak up on you. Polyols are usually only found in “diet” foods, as they are low-calorie sweeteners. If you never consume those, you may think you’re safe from them, but many liquid medications like cough syrup actually contain these sugar alcohols [12]. So, in general, check everything you consume for FODMAPS.

That being said, you don’t need to cut out every single FODMAP food; the intent of the diet is that you slowly test which foods trigger symptoms and which ones don’t, cutting out whatever causes problems.

Vegetarian Diets

This one shouldn’t need too much explaining, but the vegetarian diet is such an evergreen lifestyle choice it deserves mentioning. Vegetarianism comes in a few different forms, but for the most part, is simply a diet where no animals are consumed, though animal products may be allowed depending on what type a person follows. Some of the types of vegetarianism include:

  • Vegans: no animal products at all, including things like cheese or milk
  • Lacto-ovo: no meat, poultry, or fish, but eggs and dairy are permitted
  • Lacto: same as lacto ovo, but no eggs
  • Ovo: no dairy products, but eggs are allowed
  • Partial vegetarians: may eat fish (pescatarians) or poultry, but no other meat products [13]

Vegetarianism has long been lauded for its numerous health benefits, such as lower cholesterol, lower risk for cancer, and lower risk for diabetes [13]. Generally, there’s not too much to worry about when it comes to risks, as most sources of food for vegetarians convey all the necessary macro and micro-nutrients the body needs [13]. However, if you avoid animal products entirely, you may need to take some supplements, such as vitamin b12 [13].

Diet Trends (Finding the Best Diet For You)

These seven diets still represent a lot of potential options for you to take in your health and weight loss journey. Don’t agonize over which one to go with, though; despite how some diets can be marketed, you don’t have to commit to one and one only for the rest of your life. To make it easier to pick, follow these steps:

  • Figure out what your diet goals are (weight loss, lower blood pressure, generally better health)
  • Determine which diets most closely match your goals
  • Stick with that diet for a while, probably at least several weeks to a few months
  • Evaluate how it may or may not have worked for you
  • Decide if you want to keep on it, switch to another, or even mix them together (for example, intermittent fasting paired with the Mediterranean diet)

Everybody has unique nutritional needs, so take as much time as necessary to try these trending diets and find the best one for you.

References

[1] Wikipedia. 28 August 2021. Ketogenic Diet. 10 November 2021. Web. https://en.wikipedia.org/wiki/Ketogenic_diet

[2] Rush University. 2021. The Skinny On Seven Diet Trends. 10 November 2021. Web. https://www.rush.edu/news/skinny-7-diet-trends

[3] Masood, Wajeed; Annamaraju, Pavan; Uppaluri, Kalyan R. January 2021. Ketogenic Diet. NCBI. 10 November 2021. NCBI. https://www.ncbi.nlm.nih.gov/books/NBK499830/

[4] Harvard Health Publishing. 31 August 2021. Should you try the keto diet? 10 November 2021. Web. https://www.health.harvard.edu/staying-healthy/should-you-try-the-keto-diet

[5] Harvard Health Publishing. 10 March 2020. Intermittent fasting: Surprising update. 10 November 2021. Web. https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156

[6] Salas-Salvadó, Jordi, MD, PhD; Fernández-Ballart, Joan, MD, PhD; Ros, Emilio MD, PhD; et al. 13 May 2008. Effect of a Mediterranean Diet Supplemented With Nuts on Metabolic Syndrome Status. JAMA Internal Medicine. 11 November 2021. Web. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/773456

[7] Franquesa, M., Pujol-Busquets, G., García-Fernández, E., Rico, L., Shamirian-Pulido, L., Aguilar-Martínez, A., Medina, F. X., Serra-Majem, L., & Bach-Faig, A. (2019). Mediterranean Diet and Cardiodiabesity: A Systematic Review through Evidence-Based Answers to Key Clinical Questions. Nutrients, 11(3), 655. https://doi.org/10.3390/nu11030655 

[8] National Heart, Lung, and Blood Institute. n.d. DASH Eating Plan. Health Topics. 11 November 2021. Web. https://www.nhlbi.nih.gov/health-topics/dash-eating-plan

[9] Harvard T.H. Chan School of Public Health. 2021. Diet Review: Paleo Diet for Weight Loss. 11 November 2021. Web. https://www.hsph.harvard.edu/nutritionsource/healthy-weight/diet-reviews/paleo-diet/

[10] Challa, Hima J.; Bandlamudi, Manay; Uppaluri, Kalyan R. January 2021. Paleolithic Diet. 11 November 2021. NCBI. https://www.ncbi.nlm.nih.gov/books/NBK482457/

[11] Harvard Health Publishing. 17 September 2019. Try a FODMAPs diet to manage irritable bowel syndrome. 11 November 2021. Diet and Weight Loss. https://www.health.harvard.edu/diet-and-weight-loss/a-new-diet-to-manage-irritable-bowel-syndrome

[12] UVA Nutrition. December 2016. Low FODMAP Diet. 11 November 2021. GI Nutrition. https://med.virginia.edu/ginutrition/wp-content/uploads/sites/199/2018/05/Low_FODMAP_Diet_12.16.pdf

[13] Harvard Health Publishing. 15 April 2020. Becoming a vegetarian. 11 November 2021. Staying Healthy. https://www.health.harvard.edu/staying-healthy/becoming-a-vegetarian

About the Author

Nathan

Nathan has been a fitness enthusiast for the past 12 years and jumps between several types of training such as bodybuilding, powerlifting, cycling, gymnastics, and backcountry hiking. Due to the varying caloric needs of numerous sports, he has cycled between all types of diets and currently eats a whole food diet. In addition, Nathan lives with several injuries such as hip impingement, spondylolisthesis, and scoliosis, so he underwent self-rehabilitation and no longer lives with debilitating pain.