Brooke Ellison, MS, RDN
Sports Performance Dietitian & Education Coordinator | Sports Performance & Fitness


Nicolette Leffler, MS, RDN
Sports Performance Dietitian & Education Coordinator | Sports Performance & Fitness


Have you overheard your coworkers talking (or perhaps complaining) about their latest and greatest diet? Or has your teammate finally found thee diet that is going to make him better, faster, stronger? Are you completely confused when they start talking about ketones, voluntary daily fasts, the Paleolithic era, or carbohydrate cycling (is this something to do with eating carbs on a bike?)

Don’t worry—we’re here to help! With so many new diets popping up over the last few years, it’s easy to lose track of what’s what. More importantly, it can be difficult to know how many of them are actually effective and sustainable.

We’ve laid out five popular diets and provided definitions, basic information, and some pros and cons of each.

What it is: This diet excludes all animal products. Like the vegetarian diet, the vegan diet does not include meat, but vegans also chose not to consume dairy, eggs or any other products of animal origin. This choice can be made for a variety of reasons, including ethics, environmental concerns, and desire to improve health. The vegan diet emphasizes whole grains, fruits, vegetables, nuts, seeds and healthy fats.


• The vegan diet is lower in saturated fat—the type of fat that comes from animal sources, like meat and dairy products.
• Vegans tend to eat more fruits and vegetables, thus yielding the awesome benefits of vitamins, minerals, antioxidants, fiber, etc. Plant nutrients provide anti-inflammatory benefits, and high fiber content may improve digestion.
• Following a vegan diet can promote weight loss. Eating more high fiber foods (fruits, vegetables, whole grains) may increase the feeling of fullness and naturally reduce the amount of calories consumed.


• This diet poses a risk for micronutrient deficiencies: vitamin B12, vitamin D, calcium, omega-3 fatty acids, iron and zinc.
• There is the potential to become a “junk food” vegan, as most processed foods are technically vegan.

What it is: A very low or no carb food plan that forces the body into a state of ketosis—when your body burns fat for energy instead of carbohydrates. It also turns fat into ketones in the liver, which can supply energy for the brain. The standard keto diet is 75% fat, 20% protein, 5% carbohydrate. This diet includes meat, fish, eggs, cheese, non-starchy vegetables, and healthy fats. It eliminates fruits, grains, legumes, and anything with added sugar.


• The keto diet can be beneficial for short-term, rapid weight loss.
• It helps regulate blood sugar levels.
• Keto dieters may experience an improvement in energy levels.
• It can be effective in symptom reduction, slowed disease progression, and/or improvement in overall health for people with epilepsy or diabetes and women with polycystic ovarian syndrome. *Consult your doctor before trying this diet if this pertains to you.


• This is an extremely strict diet. To stay in a state of ketosis, dieters must consistently maintain a certain (very low) percentage of carbohydrates.
• The keto diet lacks scientific research on long-term effects and is not recommended as a long term eating pattern.
• Keto dieters usually experience the “keto flu” in the beginning, which includes symptoms such as headaches, fatigue, dizziness, brain fog, etc.
• Following this diet may affect heart health due to high amounts of saturated fats and animal proteins.
• This diet doesn’t emphasize the quality of foods.

What it is: The paleo diet, also known as “the ancestor diet,” was designed to resemble what our hunter-gatherer ancestors ate thousands of years ago: whole, unprocessed foods. The diet includes meat, fish, eggs, vegetables, fruits, nuts, seeds, herbs, spices, healthy fats, and oils. It eliminates processed foods, sugar, soft drinks, grains, dairy, legumes, artificial sweeteners, vegetable oils, margarine, and trans fats.


• Paleo dieters don’t eat processed foods, which eliminates additives, preservatives, or chemicals.
• Following a paleo diet may help with weight loss.
• This diet may improve satiety (feeling of fullness) due to higher intake of protein and fats.
• Dieters can reap anti-inflammatory benefits from plant nutrients.
• This diet is simple to follow because there is a clear list of foods that you can and cannot eat.


• The paleo diet limits grains, which are a large carbohydrate source, especially for athletes.
• This diet can be difficult for vegetarians to follow, especially since it excludes beans.

What it is: There are many different versions of intermittent fasting (IF), in which the regular 12-hour fasting window from dinner to breakfast is pushed to 14 or even 20 hours. The most common practice is the 16:8 method where you have an 8-hour eating window each day. The specific hours are up to the individual, but many find that eating from 12 p.m. to 8 p.m. is the easiest format. Basically, you eat the same amount of food you normally would, just in a shorter amount of time.


• Intermittent fasting promotes weight loss.
• It helps regulate insulin resistance. Our bodies produce insulin when we eat and digest food. In other words, fasting gives the body a break from producing insulin.
• Following this diet can be beneficial for improved energy and focus.
• IF does not reduce calories or require specific foods to be eliminated.
• IF may help preserve lean muscle mass.


• Breakfast is “delayed.” This may be difficult for those who are used to eating first thing in the morning.
• Some women may experience hormonal imbalances with longer fasts.

What it is: Once only popular among elite athletes and bodybuilders, carb cycling has made its way into the market of everyday athletes. This diet involves adjusting carbohydrate intake based on your changing needs throughout the week, month, or year. Usually, carb cycling revolves around a person’s training schedule and involves a cycling of low-carb and high-carb days. It aims to time carbohydrate intake to when it provides maximum benefit (i.e. surrounding tough, high-intensity workouts) and avoids carbs when they’re not needed (to teach the body to burn fat as fuel).


• This diet pattern doesn’t involve calorie counting or restrictions.
• Carb cycling may help with weight loss, satiety and cravings, balancing hormones and energy.
• Cycling carbs can help athletes more efficiently power their workouts and benefit performance.
• Carb cycling can benefit lean muscle growth and improve body composition.
• This eating pattern doesn’t require completely cutting out a food group.


• It may take time to determine the amount of carbs you need. Allow time for experimenting.
• Carb counting knowledge and skills are necessary to properly practice cycling.
• The research is relatively new and long-term effects of flip-flopping between low and high carb intake are unknown.

There’s no telling whether these trending diets are here to stay or will fade away, but hopefully we’ve helped you decipher what your teammate, coworker, or “that guy at the gym” are talking about. We can’t sign-off without mentioning that this was just a quick overview, and definitely do your research before adopting a new diet. Be mindful that eliminating foods and food groups does not necessarily mean you are eating healthier, and it can lead to deficiencies if diets are not carefully planned. Fueling your body with adequate nutrients (in appropriate amounts, at specific times) is necessary to achieve optimal results. This is especially true for athletes. We advise speaking with a dietitian for personalized recommendations. Everyone has different needs, and individual diets vary depending on calorie and nutrient needs, the type and amount of activity you do, and your specific goal(s).

In the end, remember that eating a healthy, balanced diet, exercising, and sleeping at least 7 hours per night will help you feel great and benefit overall health. Trends come and go, but healthy eating never goes out of style.

Nutrition for the win!

Brooke & Nicolette


Amidor, Toby. “Paleo: Spotlight on the Paleo Diet - Today's Dietitian Magazine.” Today's Dietitian, Feb. 2018, 0218p14.shtml.

Barnosky, Adrienne R., et al. “Intermittent Fasting vs Daily Calorie Restriction for Type 2 Diabetes Prevention: a Review of Human Findings.” Translational Research, vol. 164, no. 4, 2014, pp. 302–311., doi:10.1016/j.trsl.2014.05.013.

Mcswiney, Fionn T., et al. “Keto-Adaptation Enhances Exercise Performance and Body Composition Responses to Training in Endurance Athletes.” Metabolism, vol. 81, 2018, pp. 25–34., doi:10.1016/j.metabol.2017.10.010.

Rogerson, David. “Vegan Diets: Practical Advice for Athletes and Exercisers.” Journal of the International Society of Sports Nutrition, vol. 14, no. 1, 2017, doi:10.1186/s12970-017-0192-9.

Volek, Jeff S., et al. “Rethinking Fat as a Fuel for Endurance Exercise.” European Journal of Sport Science, vol. 15, no. 1, 2014, pp. 13–20., doi:10.1080/17461391.2014.959564.