Dr Renae Thomas, Medical Doctor
Are you “doing everything right” but finding that the abundant energy you’ve seen in others eating plant-based is eluding you? Whilst of course everyone has a different background and lifestyle, and it is important to see a medical professional to rule out serious causes of fatigue first, there are a few questions that you can ask yourself in the meantime of which, your clinician can assist you to healthily address. We asked Dr Renae Thomas, Loma Linda Medical Doctor and plant based legend, if she could help us to understand the root cause of fatigue and how to ensure that we can leap out of bed every morning, and to thrive all day long!
Question One: Am I striving to be too thin?
In a weight obsessed world, many people find themselves at, or attempting to be at too low a weight or body fat level to function optimally. Whilst hotly debated, the Body Mass Index (BMI) can be helpful to calculate as a baseline minimum healthy weight. If you are feeling tired and are clinically underweight by BMI chart, or trying to lose weight, either too rapidly, or once already within, or close to, a healthy weight range, it is likely that the behaviors you are using to suppress your body weight (undereating and/or over-exercising) are contributing to your lack of energy. This should be addressed by enlisting professional help, starting with a medical doctor, dietician and/or psychologist, if indicated. Ultimately, you should strive to be at a weight that makes you feel great, not the one you desire because you equate thin/lean/visible abs with health. To this end, plant-based eating is about eating for abundant energy, not deprivation nor weight loss.

Question Two: Am I under-eating?
If and when you pass STEP ONE, the next question is: Am I under-eating? Now this can be a challenge to figure out, but is worth experimenting with, as it is common for those eating plant-based, due to the low caloric density of many plant foods, and also fueled by diet-culture and unrealistic representations of health on social media. Whilst I do not recommend counting calories pretty much ever, if you are evaluating why you aren’t feeling great, a ballpark figure may be useful to ensure that you are eating enough. Most calorie calculators notoriously under-calculate calories in my experience. One of the best I have found can be found here. I would still use this as an absolute minimum, as it still seems low for many. As a ballpark estimate, very few females thrive eating less than 2,000-3,000 daily, and for males, 2,500 – 3,500 minimum per day, from whole plant foods. Even if you are meeting these as minimums, it can be worth a trial of increasing food intake, starting with an extra 200-500 calories per day, and see if this improves how you feel. Continue to increase over several weeks and re-evaluate.
Question Three: Am I eating a wide variety of foods?
Am I eating a wide variety of foods? There are many crazy diets out there, and whilst there may be case studies or anecdotal evidence that may make these seem appealing, the best evidence we have is for nutrition to be of wide variety, and predominantly from whole-grains, legumes, fruits, vegetables, nuts and seeds, and mostly unprocessed. If you have been trialing something more restrictive, such as all fruit, all juice, fasting, low carb, predominately processed foods, or whatever, I recommend a trial of expanding your food choices. Whilst deficiencies are rare, there are people that may be more sensitive, or due to restriction, may be missing some vital nutrients. Some basics to start with are:
- Adequate caloric intake (see above).
- Wide variety of foods, minimal restrictions. This includes psychological restriction, such as labelling foods ‘good’ and ‘bad’, carrying pre-packed food when socializing and avoiding social events to avoid food, going on a diet, following food rules such as ‘raw’, ‘low carb’, ‘fruitarian’ etc.
- Sufficient intake from all macronutrients (carbohydrates, proteins, and fats, in their whole food forms)
- In most cases, minimal highly processed, highly refined foods, such as oils, fried foods, packaged snack foods, protein powders/bars, and other ‘brightly colored food-like products’, low in nutrients.
- A reliable source of omega three, be it an algal based, preformed DHA/EPA supplement, and/or daily flax/chia/walnuts.
- A reliable source of B12 (typically supplemental).
- A reliable source of vitamin D, to keep blood levels in range, be it sunshine or a supplement.
- A reliable source of iodine, such as regular servings of sea vegetables, or foods supplemented with iodine.
- A reliable source of selenium, such as 1 x Brazil nut a few days a week.
- Sufficient iron rich foods (or supplement if indicated) to keep levels in healthy ranges, such as beans, greens, nuts/seeds, dried fruits and whole-grains.
- Eating regularly throughout the day with at least three meals, and snacks between if hungry.

Question Four: Am I digesting my food?
Am I digesting my food? A healthy gut and microbiome are essential for proper digestion of food and assimilation of the nutrients and ENERGY it contains. There are so many factors that can influence your body’s bacterial balance, such as food restriction and dieting, consuming insufficient fiber and unrefined plant foods, illness and antibiotic use, and environmental exposures. If you experience a lot of gas, bloating, and pain, the first step is to see a medical professional to ensure there is no underlying health issues, such as inflammatory bowel disease, celiac disease, SIBO, H.pylori infection, gastrointestinal infection, or other inflammation, infection or disease. Many people just need an adjustment period of a few months for the microbiome to adjust and re-establish, fed by the nutrients of a whole food plant-based diet. Some may need to follow a blended or lower fiber diet for a few months, increasing fiber slowly as the body adjusts. Some people may need evaluation and treatment for leaky gut or microbial imbalance. If digestion is a real issue I recommend seeking help from a professional to address underlying issues, possibly trial elimination diets/allergy testing, low FODMAPs temporarily, or tailored nutrition to feel your best.
Finally, if you can honestly say you have addressed and optimized all of the above, you probably need to see a medical professional and have a thorough medical history taken, medication review, and further workup to address the underlying cause. Don’t ignore your body’s warning signs!
Stay strong and positive, the mind influences our health to a great deal, beyond what we probably can even image. Work through the steps, it may take some time, but your issues did not develop overnight either! Don’t feel afraid, ashamed or feel like you have to struggle in silence! Reach out, get help, be honest with yourself and others and start healing! To health, happiness, and no longer feeling fatigued!

To learn more about Dr Renae*, visit her website or Instagram.
*Dr Renae Thomas, MD, B-BMed (Nutrition and Exercise Physiology), MBBS (Honours), is an Australian-born, Family and Preventive Medicine Resident, in Blue Zone Loma Linda, California. Renae is completing a masters in Public Health (Population Medicine), is a published co-author on vegetarianism and cancer, an international speaker on nutrition and health, has completed an internship at True North Health Centre in 2016, is the co-Vice President of the American College of Lifestyle Medicine Trainees, is on the lifestyle track committee for the American College of Preventive Medicine, is a PCRM (Physicians Committee for Responsible Medicine) spokesperson, a McDougall Starch Solution and Dietary Therapy graduate, and a qualified yoga teacher.
As noted in the disclaimer below, whilst the internet is an excellent source of education, it should never be used to replace professional healthcare. Please refer to your local GP or to a qualified psychologist if necessary.