The Impact of Supplements on Sports Performance for the Trained Athlete

The Impact of Supplements on Sports Performance for the Trained Athlete: A Critical Analysis

Elite athletes often use nutritional supplements to improve performance and gain competitive advantage. The prevalence of nutrient supplementation ranges from 40% to 100% among trained athletes, yet few athletes have a trusted source of information for their supplement decisions and expected results. This critical analysis review evaluates systematic reviews, meta-analyses, randomized control trials, and crossover trials investigating commonly used supplements in sport: caffeine, creatine, beta-alanine (β-alanine), branched chain amino acids (BCAAs), and dietary nitrates. By reviewing these supplements’ mechanisms, evidence relating directly to improving sports performance, and ideal dosing strategies, we provide a reference for athletes and medical staff to personalize supplementation strategies.

Whole Food Plant-Based Diet

Whole Food Plant-Based Diet

By Julia Pangalangan

The Standard American diet contributes significantly to risk of disease, mortality, and morbidity in the United States. In contrast, dietary patterns emphasizing a whole food, plant-based approach to eating promotes health and longevity. A whole food, plant-based (WFPB) dietary pattern involves consuming a variety of vegetables, legumes, nuts, seeds, fruits, mushrooms, herbs, and grains. A plant-based approach can be difficult to implement, but even small, incremental changes can be extremely impactful. Increasing intake of minimally processed foods can help to prevent and manage chronic diseases. A plant-forward approach to eating is not a diet, but a lifestyle to move towards. 

Dr. Marily Oppezzo, RD, PhD is an educational psychologist at Stanford University and her research focuses on behavioral approaches to improve health and well-being. I was able to sit down with Dr. Oppezzo to discuss why this type of eating is so challenging for most of us. She used her expertise as a behavioral and learning scientist and her experience as a registered dietician to share helpful insights. 

Firstly, Dr. Oppezzo emphasizes that following a plant-forward approach does not require you to become a vegan or a vegetarian. After all, some vegan foods require a lot of processing and highly processed foods are typically higher in sodium, saturated fat, and sugar. Instead, think about food with minimal processing like homemade maple-glazed carrots or a veggie stir-fry. Dr. Oppezzo would suggest a plate rich in diverse vegetables and whole grains even if that plate also includes chicken. As Americans, we are used to the western diet which is high in meat and prepackaged food, but substituting these for plants and whole grains can have tremendous benefits for our health.

Many people want to change their eating patterns, but change can be hard when the typical western diet has been made so easy. However, making a sustained effort to increase whole foods in one’s diet may help individuals with a variety of health concerns. For instance, an individual may feel their energy is plateauing throughout the day. Another may notice their blood pressure creeping higher at every doctor’s appointment. For some, they already have a chronic disease diagnosis, and they want to manage it well. Despite the large amount of scientific evidence highlighting the potential health benefits of a WFPB diet, making these changes can come with a variety of roadblocks. Dr. Oppezzo believes one major reason for this is because of the continuous flood of marketing campaigns and fad diets. “Dump butter in your coffee, bacon is back, and lose 2 pant sizes by summer,” Dr. Oppezzo listed as she considered all of the dietary claims she has heard. In comparison to these marketing claims, choosing less processed and more green things and making moderate changes rather than drastic ones is quite boring. These phrases and advertisements are made to be alluring but they lack the research backing of a plant-predominant dietary pattern and may lead to unsustainable eating habits. Aesthetic-based fad-diets, supplements, and detoxes are prevalent in marketing, and media often emphasizes visual changes as markers for health instead of how your body and mind feel. A plant-forward diet instead helps you meet your energy needs, tastes delicious, and has been scientifically proven to increase your overall health, longevity, and to help you feel your best.

Moreover, many fad diets tend to leave individuals feeling depleted. These diets often rely on an all or nothing approach — where one must cut out entire food groups and restrict calories. In contrast, a plant-predominant eating pattern is not a diet change but a lifestyle change. To get started, instead of banning all carbs and eliminating all of your favorite foods, Dr. Oppezzo recommends setting up a gradual plan and making one change to your diet per week. Challenge yourself to swap a sugary beverage for herbal tea, remodel your fridge to have the fruits and vegetables front and center, or add one new nutritious food to your grocery list. 

Furthermore, Dr. Oppezzo recommends eating regular meals and snacks to ensure we are meeting our energy needs. If you’re feeling hungry make sure to listen to your body and satisfy that hunger. But, Dr. Oppezzo also recommends being mindful when you are wandering into the snack cabinet if you are bored or upset. This may be a sign that something else is going on such as stress or sleep deprivation. If we can recognize these moments, we can make the choice to call a friend, go for a walk, or engage in something restful instead. 

For more thoughts and tips from a dietician, check out Stanford’s BeWell’s Ask the Dietician.  


How to transition to a plant-predominant diet:

  • Set SMART goals: specific, measurable, attainable, relevant, and time-bound.

A plant-based diet can have substantial short-term and long-term benefits. However, it also has its challenges. It is important to identify why it is important to you to eat a plant-based diet. Try to write a few health goals that are personally meaningful to you. How important is it that you accomplish these goals? How will consuming a plant-based diet help you achieve these goals?

Setting SMART Goals — 

Instead of:

“I am going to eat only whole foods from now on. No exceptions!”


“I am going to include one vegetable at lunch and one at dinner on the weekdays.”


This goal is specific, easy to measure, achievable given a busy lifestyle, and has a time associated.


  • Address the built environment

Our environment influences our decisions and behaviors. It is essential to set up your environment for success. This is particularly important when we are tired and stressed. When you come home from a long day and open the fridge, do you see ready-to-eat veggies and dip? Do you find an empty fridge and immediately open DoorDash? Do you rummage through the pantry to grab a bag of chips or crackers?

If we have set up our environment for success, we can make the healthy choice the easy choice. Here are some ideas for how to set up your environment for success:

  1. Stock up on the good stuff: Make sure to have lots of your favorite fruits and veggies available for the week. Frozen or canned produce are great to have on hand because they are inexpensive, and they last a long time. Lentils, beans, and chickpeas are a wonderful source of plant-based protein that can be added to make any meal more satisfying. 
  2. Enjoy your favorite meals: You don’t need to buy the latest vegan cookbook. You may be surprised how easy it is to make your favorite meals plant-based! Try using Dr. Oppezzo’s one change strategy. Consider a meal you regularly make and then add a vegetable or swap a refined grain for a whole grain.
  3. Make a plan: A plant-based diet can feel overwhelming when we are hungry or short on time. Write a list of easy, quick meals that you feel confident you can make at any time. You can save time by planning to make extra of your meals so you can use them for lunches throughout the week. It can also be helpful to have a list of healthy take-out options


  • It’s a group effort (rely on support, talk to loved ones, seek a community of like-minded individuals)

It can feel hard to eat well if those around you do not. Who in your life is supportive of your desire to eat healthy? If you haven’t already, have a conversation with your loved ones to let them know about your health goals. If you feel that you need more support, try joining groups on Facebook . You can also look for groups at gyms and community centers. 

If you are involved at Stanford, check out the BeWell  program resources. If you are not affiliated with Stanford, check to see if your employer offers any wellness programs.  


  • Focus on what you get to eat

Many people are hesitant to begin a whole food, plant-based approach because of all of the foods they will have to give up. Instead of dwelling on what you are trying to eat less of, consider all that you get to eat in a day. Try using Dr. Gregor’s “Daily Dozen” as a self checklist. He includes foods like beans, berries, cruciferous vegetables, nuts, and spices. Challenge yourself to add in one new food each week. When you’re trying to eat more items from the Daily Dozen, you won’t be so consumed with the foods you are eating less of. It is less about restricting “bad” foods — It is more about trying to increase your intake of healthful and nourishing foods. 


  • Keep it simple (easy and quick staple recipes that you can have on rotation)

Eating a plant-based diet does not mean making fancy new recipes every night or buying expensive green juice and Impossible burgers. It is critical to find what works well for you. Again, what meals do you and your family enjoy? Can you add a new vegetable to that meal? What would it look like to swap a refined grain for a whole grain source?

If you are looking to try some new recipes, there are plenty of wonderful resources. Stanford’s BeWell program has several great suggestions. I also love Forks Over Knives and Ornish Lifestyle Medicine.  


It is not important that we have the perfect diet, but that we have a diet that fuels us and makes us feel our best. Through introducing more whole and plant -based foods into your diet you can make sustainable changes towards a healthier you. Each meal we eat is a new chance to make a healthy decision for our long-term health. A whole food, plant-based eating pattern is not a diet. It is a lifestyle change to promote quality of life and longevity.

Olive oil consumption

Consumption of Olive Oil and Risk of Total and Cause-Specific Mortality Among U.S. Adults – JACC

A diet that includes approximately half a tablespoon of olive oil daily may cut risk for CV death and all-cause death by 19%, according to research published in the Journal of the American College of Cardiology.

Fruits and Vegetables

Fiber Boosts Melanoma Treatment – Science

A high-fiber diet may improve patients’ response to immunotherapy treatment for melanoma. That’s the conclusion of a large international study led by researchers at the University of Texas and the National Institutes of Health. The fifth most common type of cancer in the United States, melanoma is also the deadliest form of skin cancer, responsible for more than 7,000 deaths every year. Immune checkpoint blockade (ICB) therapy uses certain drugs to block proteins produced by some malignant cells, which allows the immune system to better fight cancer.

healthier eating habits

Active Voice: Diet Manipulation for Healthy Living – Importance of 16-Hour Fasting – ACSM

Social media commonly offers a variety of healthy living solutions, presenting a perfect mix of speculation, firm belief, a bit of scientific evidence and personal experience. Nutrition tends to be a popular topic on social media. Often, a seemingly convincing case is made that encourages people that a dietary approach is miraculous. One such topic is prolonged fasting. As health practitioners, we often have clients mention this “new” approach to healthy living. However, the approach often has little-to-no scientific evidence.

fitness lifestyle

Supplements May Head Off Autoimmune Disease – American College of Rheumatology

When it comes to protecting against autoimmune diseases such as rheumatoid arthritis, polymyalgia rheumatica, and psoriasis, a pair of supplements may be helpful. That’s the finding of a recent study by researchers at Harvard Medical School and its affiliates. They analyzed data from VITAL, the largest national randomized, controlled trial to look at the effects of vitamin D3 and omega-3 fatty acid supplements on the risk of autoimmune disease.

Navigating the Difficult World of Supplements

Active Voice: Can Creatine Supplementation Improve Properties of Muscle and Bone Mass in Older Adults? – American College of Sports Medicine

After the fourth decade of life, muscle and bone mass decrease by ~ 1%-2% per year. This age-related reduction in muscle and bone (including muscle density and bone geometry, as indicators of muscle and bone quality) increases the risk of falls and fractures. Approximately one-in-three older adults experience a fall each year, with many experiencing multiple falls. Falls may lead to physical inactivity and premature morbidity. Therefore, lifestyle interventions that improve properties of muscle and bone may potentially reduce the risk of falls and fractures in older adults.

Doctors Group Says Plant-Based Diet Could Be Prescription for Arthritis Pain – Physicians Committee for Responsible Medicine

new report shows that one in four Americans has arthritis. The reason, according to the nonprofit Physicians Committee for Responsible Medicine, may be food choices. The good news is that a plant-based diet may help.


Crosstalk among intestinal barrier, gut microbiota and serum metabolome after a polyphenol-rich diet in older subjects with “leaky gut” – Clinical Nutrition

The MaPLE study was a randomized, controlled, crossover trial involving adults ≥60 y.o. (n = 51) living in a residential care facility during an 8-week polyphenol-rich (PR)-diet. Results from the MaPLE trial showed that the PR-diet reduced the intestinal permeability (IP) in older adults by inducing changes to gut microbiota (GM). The present work aimed at studying the changes in serum metabolome in the MaPLE trial, as a further necessary step to depict the complex crosstalk between dietary polyphenols, GM, and intestinal barrier.


A fermented-food diet increases microbiome diversity and lowers inflammation, Stanford study finds – Stanford Medicine