Plant-Based Diet: Why Am I Always Feeling Tired?

A plant-based diet can be a healthy choice, but it's important to be aware of some common pitfalls that can leave you feeling tired. Firstly, it's easy to under-eat on a plant-based diet, especially if your goal is weight loss. Not consuming enough calories can lead to low energy levels throughout the day. Secondly, vitamin and mineral deficiencies can play a role. For example, vitamin B12 and iron are more readily available from animal sources, so plant-based diets need to be carefully planned to ensure adequate intake. Finally, a sudden change in diet can be challenging for your body to adjust to, and you may experience fatigue while it adapts to your new way of eating.

Not eating enough calories

Transitioning to a plant-based diet can result in a significant decrease in calorie intake, which can lead to low energy levels. This is because the body needs a certain amount of calories to function properly and perform basic activities such as breathing, digesting food, and pumping blood. This number of calories is known as the Basal Metabolic Rate (BMR). On top of the BMR, the body also requires additional calories for daily activities and exercise.

To ensure adequate calorie intake, it is important to calculate your BMR and then add on calories for your activity level, known as the Active Metabolic Rate (AMR). For example, if you are sedentary and do little to no exercise, your AMR would be calculated as BMR x 1.2. In contrast, if you are very active and engage in hard exercise 6-7 days a week, your AMR would be calculated as BMR x 1.9.

Tracking your calorie intake for a few days can help you understand if you are consuming enough calories to meet your BMR and AMR. If you are not eating enough calories, you can gradually increase your portion sizes and focus on including more calorie-dense plant-based foods in your diet, such as nuts, seeds, nut butters, tahini, tofu, tempeh, whole grains, lentils, and avocados.

Additionally, including a smoothie as a snack between meals can be a delicious and easy way to boost your calorie intake. Smoothies made with nut butter, fruit, oats, and flaxseeds or chia seeds can provide extra energy without feeling like an extra meal.

Lack of vitamin B12

Vitamin B12 is responsible for converting glucose to energy. Humans are not able to make their own vitamin B12; it is made from microorganisms in an animal's intestines or diet. As plants are unable to make vitamin B12, vegan foods tend to have low levels of this vitamin.

Vitamin B12 is essential for nerves and red blood cells, which carry oxygen around the body. A deficiency in vitamin B12 can lead to anaemia, causing feelings of fatigue as the body does not have enough red blood cells to carry oxygen.

Symptoms of vitamin B12 deficiency include heart palpitations, a loss of balance, cognitive changes (such as depression, memory impairment, confusion, psychosis, and tiredness), and dyspnoea. Neurological complications may also occur, causing loss of sensation, postural hypotension, muscle weakness, or loss of mental and physical drive.

Vitamin B12 deficiency can occur without developing anaemia and often neurological symptoms are more commonly observed. Therefore, it is recommended to get your blood vitamin B12 levels monitored, particularly if no B12-containing supplements have been taken in the last 3-6 months.

The recommended daily intake of vitamin B12 for the average US adult is 2.4 micrograms. For pregnant and breastfeeding women, the recommended intake is 2.6 and 2.8 micrograms, respectively.

Vegans and those who have not eaten eggs, dairy, and meat for more than five years are at risk of vitamin B12 deficiency. To combat this, it is recommended to take a daily vitamin B12 supplement and consume B12-fortified foods such as plant milk, breakfast cereals, nutritional yeast flakes, and marmite.

Lack of iron

Iron is an essential mineral for proper growth and development, and it plays a crucial role in various bodily functions. It is needed to make hemoglobin, a protein in red blood cells that carries oxygen from your lungs to all parts of your body. Myoglobin, another protein made by iron, brings oxygen to your muscles.

Iron deficiency can lead to low energy levels and fatigue. This is because iron transports oxygen throughout the body, and without enough iron, you may experience a lack of oxygen in your muscles, resulting in feelings of tiredness. An iron deficiency can also cause breathlessness, headaches, irritability, dizziness, or anemia.

There are two types of iron: heme and non-heme. Heme iron is found in animal products and is easily absorbed by the body. Non-heme iron, on the other hand, is derived from plant sources and is not absorbed as well. Examples of plant-based sources of non-heme iron include dried beans and legumes, dark green leafy vegetables, dried fruits, nuts and seeds, wholegrain cereals and breads, and iron-fortified products.

Since the body doesn't absorb non-heme iron as efficiently as heme iron, it is important for those on a plant-based diet to ensure they are getting enough iron. The recommended daily intake of iron is higher for those on a plant-based diet, with vegetarians and vegans requiring 1.8 times more iron than meat-eaters, or about 32 grams per day.

To enhance the absorption of non-heme iron, it is recommended to consume vitamin C-rich foods alongside iron-rich plant foods. Vitamin C has been shown to improve iron absorption. Good sources of vitamin C include oranges, kiwi fruits, strawberries, tomatoes, capsicum, and lightly cooked broccoli. Additionally, using cast-iron cookware may also increase iron intake as a small amount of iron may be transferred to the food during cooking.

Lack of zinc

Zinc is an essential mineral that supports the immune system and metabolism. It is readily available in many plant foods, including tofu, tempeh, legumes, grains, nuts, and seeds, especially pumpkin seeds. However, vegans and vegetarians may be at risk of zinc deficiency due to the reduced bioavailability of zinc from plant sources.

Phytates, commonly found in plant foods, reduce the absorption of zinc in the body. This can lead to a zinc deficiency, which is characterised by impaired immune function, loss of appetite, growth retardation, weight loss, taste abnormalities, and lethargy.

To maximise zinc absorption on a plant-based diet, it is recommended to include sprouted or soaked grains and legumes, toasted nuts and seeds, or wholegrain breads made from yeast or sourdough. These sources of zinc have lower levels of phytates, which can impact zinc absorption.

If you are feeling tired and suspect a zinc deficiency, it is important to consult your doctor and get your bloodwork tested. They may recommend a modest zinc supplement or suggest including more zinc-rich plant foods in your diet.

Not enough sleep

If you're feeling tired on a plant-based diet, one of the most obvious reasons could be that you're simply not getting enough sleep. Most people need 7-8 hours of sleep per night to feel well-rested. If you're waking up at 5 or 6 am to work out and going to bed at 11 pm, you're probably not getting enough sleep. Try making a log of your sleep and wake times for a few days. If you're consistently sleeping less than 7 hours per day, try going to bed an hour earlier.

The Link Between Plant-Based Diets and Sleep

Interestingly, studies have shown that people on plant-based diets tend to get more sleep. Vegetarians and vegans sleep 36 minutes more per night than average, with up to 90% reporting good or excellent sleep quality. A separate study of 2,424 people aged 45 or older in China found that those who consumed more whole grains, fruits, vegetables, nuts, and legumes experienced significantly better sleep quality.

Adopting a plant-based diet may not only positively impact your physical health but may also contribute to a good night's sleep, improving your overall well-being.

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