Vegan Diet: Why Am I So Tired?

A vegan diet is often associated with increased energy levels. However, some people may find themselves feeling more tired or fatigued after adopting a vegan lifestyle. This can be attributed to several factors, including not consuming enough calories, lacking certain vitamins and minerals, or not eating a diverse range of nutrient-dense foods. A well-balanced vegan diet should include a variety of whole foods such as fruits, vegetables, pulses, whole grains, nuts, and seeds to ensure adequate nutrient intake and sustained energy levels throughout the day.

Lack of specific vitamins and minerals

A vegan diet can be healthy, but it is important to ensure you are getting enough nutrients. A common issue for people new to a vegan diet is experiencing low energy. This can be caused by a lack of specific vitamins and minerals in your diet.

Vitamin B12

Vitamin B12 is responsible for converting glucose to energy. Humans are unable to make their own vitamin B12, and it is not found in large quantities in vegan foods. Vitamin B12 is one of the most crucial vitamins for good health, and a deficiency can lead to fatigue, weakness, decreased stamina, shortness of breath, and even palpitations. It is also required for nerve cell function, as well as the spinal cord and brain. A deficiency can result in mental changes including confusion, depression, irritability, insomnia, and poor concentration—all of which can result in fatigue.

Iron

Iron is another nutrient that contributes to energy levels. It transports oxygen throughout the body, and a deficiency can lead to fatigue due to a lack of oxygen in the muscles. Iron is harder to come by on a plant-based diet, as plant-based iron is not absorbed as well as iron from animal sources.

Vitamin C

Vitamin C is important for converting fat into energy. While a deficiency is unlikely on a whole food plant-based diet, it is possible for those relying on processed vegan food products.

Vitamin D

Vitamin D helps to maintain adequate levels of calcium and phosphate, which are important for building and strengthening bones and muscles. A deficiency can lead to fatigue as a result of weakened bones and muscles. Vitamin D is produced in the skin when exposed to sunlight, but it can also be acquired from food such as fish, milk, and mushrooms.

Iodine

Iodine is required for the production of thyroid hormones, which help to regulate energy metabolism. A drop in iodine intake can cause fatigue, lethargy, weakness, and tiredness.

How to increase vitamin and mineral intake

• Take supplements: A daily B12 supplement of 10mcg, or a weekly supplement of 2000mcg is recommended. Vitamin D supplements are also recommended during winter months.
• Fortified foods: Consume fortified foods such as B12-fortified nutritional yeast or plant-based milk.
• Plant-based sources: Increase your intake of plant-based sources of iron, such as lentils and pulses, and iodine, such as sea vegetables (nori, dulse, or wakame).
• Vitamin C and iron: Eat vitamin C-rich foods alongside iron-containing foods to increase the absorption of iron.
• Calcium: Look for calcium-fortified foods such as cereals and juices, as well as consuming tofu, edamame, and dark green vegetables.

Not eating enough

It is common for people transitioning to a plant-based diet to not eat enough calories throughout the day. This is because vegan diets are more nutrient-dense than calorically dense, meaning you eat many nutrient-rich plant foods with lower amounts of calories per serving. As a result, you may feel hungrier more frequently than non-vegans.

To ensure you are eating enough, you can calculate your basal metabolic rate (BMR) – the number of calories your body needs for basic functions like breathing, digesting food, and pumping blood. Your BMR will depend on your sex, weight, height, and age. On top of your BMR, your body also needs calories for daily activities like walking and chores, as well as for exercise.

If you are not taking in enough calories to cover your BMR and AMR (active metabolic rate), you may experience low energy levels. To remedy this, you can eat enough calories to cover your BMR and then add on for AMR. You can also try snacking between meals, eating bigger portion sizes, and eating until you are about 80% full.

Not eating enough protein

Protein is one of three macronutrients our bodies use for energy, the other two being carbohydrates and fats. Amino acids are the building blocks of protein, and are vital to our bodies for building and repairing cells, creating enzymes and antibodies, and performing other essential functions.

It is a common misconception that vegan diets lack sufficient protein. However, vegans can get protein from various plant sources. It is important to note that a well-planned vegan diet is considered beneficial for all stages of life, but those including large amounts of ultra-processed plant foods are not.

If you are feeling tired on a vegan diet, you may not be eating enough protein-rich foods. The amount of protein you need depends on your body weight, sex, and activity level. For example, the U.S. recommended daily allowance of protein is 0.8 grams per kilogram of body weight (0.36 grams per pound) for the general population. However, vegan athletes may need more protein, with some sources recommending up to 25-30% of their daily caloric intake from protein.

• Seitan: 25 grams of protein per 3.5 ounces
• Tofu, tempeh, and edamame: 12-20 grams of protein per 3.5 ounces
• Lentils: 18 grams of protein per cooked cup
• Beans: 15 grams of protein per cooked cup
• Nutritional yeast: 8 grams of protein per half ounce
• Hemp seeds: 9 grams of protein per 3 tablespoons
• Green peas: 9 grams of protein per cooked cup
• Spirulina: 8 grams of protein per 2 tablespoons
• Quinoa: 8-9 grams of protein per cooked cup
• Ezekiel bread: 8 grams of protein per 2 slices
• Soy milk: 6 grams of protein per cup
• Oats: 5 grams of protein per half cup dry
• Wild rice: 7 grams of protein per cooked cup
• Chia seeds: 5 grams of protein per ounce
• Nuts and seeds: 5-7 grams of protein per ounce

If you are concerned that you are not getting enough protein in your vegan diet, try incorporating more of these protein-rich plant foods into your meals and snacks. You can also speak with your doctor or a dietitian to get personalized advice and ensure that you are meeting your protein needs.

Not eating enough carbohydrates

Carbohydrates are an essential source of energy and should make up 45-65% of your diet. If you're not eating enough carbs, you may feel tired and sluggish, especially during workouts.

To ensure you're getting enough carbohydrates, include a variety of fruits, vegetables, whole grains, beans, legumes, nuts, and seeds in your diet. These foods are not only excellent sources of carbohydrates but also provide essential vitamins, minerals, and fibre.

It's important to note that not all carbs are created equal. Simple carbs, like sugar and refined flour, can cause a spike in blood sugar followed by a crash, leaving you feeling tired. On the other hand, complex carbs, found in whole foods like the ones mentioned above, provide sustained energy and essential nutrients.

Additionally, pairing carbohydrates with protein and healthy fats can help stabilise blood sugar levels and provide long-lasting energy. This is especially important for athletes or individuals with an active lifestyle.

• Make sure your meals are balanced and include a good source of complex carbohydrates.
• Include a variety of whole foods in your diet, such as fruits, vegetables, whole grains, beans, legumes, nuts, and seeds.
• Pair carbohydrate-rich foods with protein-rich foods, such as beans and legumes with whole grains.
• Choose nutrient-dense carbohydrates like hemp seeds, sesame seeds, and spinach, which provide not only carbs but also essential vitamins and minerals.
• If you're very active, aim for the higher end of the recommended carb intake, which is around 100-150 grams per day for those who exercise a lot.

By including a variety of complex carbohydrate sources in your diet and pairing them with protein and healthy fats, you can ensure you're getting enough energy to fuel your daily activities and support your health.

Not eating enough calories

One of the most common reasons for low energy levels on a vegan diet is not consuming enough calories. This is especially true for those who transition to a vegan diet to lose weight. By cutting out animal products, they may unintentionally reduce their calorie intake significantly.

The body requires a certain number of calories to function optimally. The basal metabolic rate (BMR) is the number of calories the body needs for basic functions like breathing, digestion, and blood circulation. This rate varies for each individual and can be calculated using specific formulas for men and women that take into account weight, height, and age.

In addition to the BMR, the body also needs calories for daily activities and exercise. Failing to consume enough calories to meet these energy requirements can result in low energy levels and fatigue.

To address this issue, it is important to ensure that your calorie intake covers your BMR and includes additional calories for your activity level. You can use an Active Metabolic Rate (AMR) multiplier based on your exercise frequency to determine your total calorie needs. For example, if you are moderately active and exercise 3-5 days a week, you would multiply your BMR by 1.55 to get your total daily calorie needs.

Tracking your calorie intake for a few days can help you understand if you are consuming enough calories to meet your energy requirements. If you find that you are consistently falling short, you may need to increase your portion sizes or incorporate more calorie-dense foods into your diet.

Some examples of calorie-dense vegan foods include nuts, seeds, dried fruit, nut butters, oils, avocados, grains, granola, beans, quinoa, and sweet potatoes. Additionally, drinking smoothies is a good strategy to increase your calorie intake, as it allows you to consume more calories in liquid form without feeling overly full.

By ensuring that you are consuming enough calories to meet your body's energy needs, you can help address low energy levels associated with a vegan diet.

Frequently asked questions