This week I’ve answered two letters from young vegans who asked for comments about their individual diets. The things that they are doing right and wrong apply to many vegans, so I’ve reprinted their letters in full along with my response.

Most of my friends think that I’m undernourished. I honestly eat anything I want but I usually only consume about 1,000 calories per day. I also take a multivitamin and iron and calcium supplements. Are there some guidelines I could follow to meet nutrient needs. I’m a college student so I can’t afford extravagant meals. My typical diet looks like this:

This first question show how difficult it is to plan a healthful diet when the diet is too low in calories. The first diet is based on healthy foods–but it just doesn’t contain enough food to meet needs. It’s very difficult to meet protein needs on such a low calorie intake, especially since protein needs are higher when calorie intake is low. This is especially important for vegans since they have higher protein needs than omnivores. Even with the use of vitamin supplements, this diet might fall short on some trace nutrients and other important compounds found in whole plant foods. Also, it would be very difficult to maintain a normal weight over the long term on such a low calorie diet, especially if a person is engaging in adequate exercise.

The second diet makes use of a good variety of whole plant foods, including higher protein ones like tofu and beans. It includes a serving of nuts and includes good healthful snacks. Assuming the amounts are adequate, this is a good example of a pretty simple meal plan that is well-balanced.

Although the total amount of food consumed will vary depending on a person’s size and activity level, guidelines for vegan diets are pretty straightforward. First, eat plenty of complex carbohydrates: whole grains and starchy veggies. Refined, enriched grains are okay in moderation but whole grains are much more nutrient dense. Include very generous servings of vegetables and fruits. Aim for a total fruit and veggie intake of at least 8 servings per day and try to include leafy greens (kale, collards, bok choy) as often as possible since they are super rich in nutrients. A mix of cooked and raw veggies is a good idea. It’s fine to use some frozen and canned vegetables to reduce cost and preparation time.

Be sure to eat protein-rich plant foods every day like legumes and soyfoods (tofu, soymilk, tempeh, etc). Aim for at least five servings of these foods with a serving equaling _ cup beans or tofu or 1 cup soymilk. Also include a serving–just a couple of tablespoons–of nuts or seeds or nut or seed butter every day in your diet.

Then make sure you are getting at least 1,000 milligrams of calcium. Good choices are fortified soy, rice, or almond milk, calcium-set tofu, fortified orange or apple juice, leafy green veggies, some beans and nuts. This is one area where it pays to be a bit obsessive. Because vegans do often fall short on calcium, it can be a good idea to track intake. If you don’t meet recommendations, make up the difference with a supplement.

If you live in a smoggy urban area, in the north, or are dark-skinned, there is an excellent chance that you don’t make enough vitamin D. So take a supplement of this nutrient or use fortified foods daily–like fortified soy, rice, or almond milk, or breakfast cereals. Very few foods are natural sources of vitamin D.

All vegans need a source of vitamin B12 in their diet, so use a supplement or foods fortified with it.

Vegans would also do well to include a good source of omega-3 fats in their diet daily–a teaspoon of ground flaxseed (yes, it must be ground) or a tablespoon of canola oil. Other foods that offer lesser amounts of omega-3s are soy oil, tofu and walnuts. (I’ll be writing more about omega-3 fats in the next several weeks.)

Finally, be sure to eat enough food to maintain a healthy weight. Don’t skimp on fat too much and don’t avoid carbohydrates. Both of these nutrients have roles in healthful diets and eating enough food in general is crucial to good health.

So here it is in a nutshell: what you need to know about planning healthful vegan diets.

• Base your diet on whole grains
• Eat lots and lots of fruits and, especially vegetables
• Include at least five servings a day of a protein-rich plant food in your diet
• Eat a small serving of nuts or seeds (or nut or seed butter) every day
• Track your calcium intake; use a supplement if you think you may not get enough
• Eat a good source of omega-3 fats every day
• Include a supplement of vitamin B12 if you don’t use foods fortified with this vitamin.
• Ditto for vitamin D, unless you live where it is nice and sunny the year round.
• Eat enough food.