Vegetarian diet: How to get the best nutrition
A well-planned vegetarian diet is a healthy way to meet your nutritional needs. Find out what you need to know about a plant-based diet.
You may follow a vegetarian diet for cultural, religious or ethical reasons. Or you may eat a vegetarian diet to stay healthy and prevent health problems, such as cardiovascular disease. Whatever your reasons for choosing a vegetarian diet, this guide will help you make smart choices to ensure that you meet your daily nutritional needs.
Indeed, a well-planned vegetarian diet can meet the needs of people of all ages, including children, teenagers, and pregnant or breast-feeding women. The key is to be aware of your nutritional needs so that you plan a diet that meets them. If you aren’t sure how to create a vegetarian diet that’s right for you, talk with your doctor and a registered dietitian.
Types of vegetarian diets 素食的种类
When people think about a vegetarian diet, they typically think about a diet that doesn’t include meat, poultry or fish. But vegetarian diets can be further categorized into three types:
Vegan diets exclude meat, poultry, fish, eggs and dairy products — and foods that contain these products.
Lacto-vegetarian diets exclude meat, fish, poultry and eggs, as well as foods that contain them. Dairy products, such as milk, cheese, yogurt and butter, are allowed in a lacto-vegetarian diet.
Lacto-ovo vegetarian diets exclude meat, fish and poultry, but allow eggs and dairy products.
Some people follow a semivegetarian diet — also called a flexitarian diet — which is primarily a plant-based diet but includes meat, dairy, eggs, poultry and fish on occasion or in small quantities.
Getting adequate nutrition 摄取足够的营养
The key to a healthy vegetarian diet — like any diet — is to enjoy a variety of foods. No single food can provide all the nutrients your body needs. The more restrictive a diet is, the more challenging it is to get all the nutrients you need. A vegan diet, for example, eliminates food sources of vitamin B-12, as well as milk products, which are good sources of calcium. Therefore, you may need to make an extra effort to ensure that your vegetarian diet includes sufficient quantities of the following nutrients:
Calcium helps build and maintain strong teeth and bones. Milk and low-fat dairy foods are highest in calcium. Dark green vegetables, such as turnip and collard greens, kale and broccoli, are good plant sources when eaten in sufficient quantities. Calcium-enriched and fortified products, including juices, cereals, soy milk, soy yogurt and tofu, are other options.
Iodine is a component in thyroid hormones, which help regulate metabolism, growth and function of many key organs, such as the brain, heart, kidney and thyroid. Vegans may not consume enough iodine and be at risk of iodine deficiency and possibly goiter. In addition, foods such as soybeans, cruciferous vegetables and sweet potatoes may promote goiter. Because food manufacturers may not use iodized salt in processed foods, vegans may want to ensure that they use salt with iodine at the table or in cooking. Just 1/4 teaspoon provides a significant amount of iodine.
Iron is a crucial component of red blood cells. Dried beans and peas, lentils, enriched cereals, whole-grain products, dark leafy green vegetables and dried fruit are good sources of iron. Because iron isn’t as easily absorbed from plant sources, the recommended intake of iron for vegetarians is almost double that recommended for nonvegetarians. To help your body absorb iron, eat foods rich in vitamin C, such as strawberries, citrus fruits, tomatoes, cabbage and broccoli, at the same time as you’re eating iron-containing foods.
Omega-3 fatty acids are important for cardiovascular health as well as eye and brain development. Vegetarian diets that do not include fish and eggs are generally low in active forms of omega-3 fats. Because conversion of the plant-based omega-3 to the types used by humans is inefficient, you may want to consider fortified products or supplements or both.
Protein helps maintain healthy skin, bones, muscles and organs. Eggs and dairy products are good sources, and you don’t need to eat large amounts to meet your protein needs. You can also get sufficient protein from plant-based foods if you eat a variety of them throughout the day. Plant sources include soy products and meat substitutes, legumes, lentils, nuts, seeds and whole grains.
Vitamin B-12 is necessary to produce red blood cells and prevent anemia. This vitamin is found almost exclusively in animal products, so it can be difficult to get enough B-12 on a vegan diet. Vitamin B-12 deficiency may go undetected in people who eat a vegan diet. This is because the vegan diet is rich in a vitamin called folate, which may mask deficiency in vitamin B-12 until severe problems occur. For this reason, it’s important for vegans to consider vitamin supplements, vitamin-enriched cereals and fortified soy products.
Vitamin D plays an important role in bone health. Vitamin D is added to cow’s milk, some brands of soy and rice milk (be sure to check the label), and some cereals and margarines. However, if you don’t eat enough fortified foods and have limited sun exposure, you may need supplementation with vitamin D-2 (derived from plants).
Zinc is an essential component of many enzymes and plays a role in cell division and in formation of proteins. Like iron, zinc is not as easily absorbed from plant sources as it is from animal products. Cheese is a good option if you eat dairy products. Plant sources of zinc include whole grains, soy products, legumes, nuts and wheat germ.
Getting started 入门
If you’re not following a vegetarian diet but you’re thinking of trying it, here are some ideas to help you get started:
Ramp up 逐步提高
Each week increase the number of meatless meals you already enjoy, such as spaghetti with tomato sauce or vegetable stir-fry.
Learn to substitute 学会取代
Take favorite recipes and try them without meat. For example, make vegetarian chili by leaving out the ground beef and adding an extra can of black beans. Or make fajitas using extra-firm tofu rather than chicken. You may be surprised to find that many dishes require only simple substitutions.
Branch out 分支出去
Scan the Internet for vegetarian menus. Buy or borrow vegetarian cookbooks. Check out ethnic restaurants to sample new vegetarian cuisines. The more variety you bring to your vegetarian diet, the more likely you’ll be to meet all your nutritional needs.
By Mayo Clinic staff 。Mayo诊所的员工撰文
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Source > National Geographic Environment 国家地理杂志环境版
Translated by > BlogHost
Word Count > approx. 1080 words in English