Protein. Protein. Why is protein important?

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1 Protein Protein Though protein is often perceived as an area of concern for vegans, it is actually very easily accessible on a vegan diet, particularly if a variety of plant foods are consumed regularly. It is important to incorporate a variation of protein sources to keep your diet interesting and satisfying. Why is protein important? Protein is the major building block of muscle and other body tissues and is used to produce hormones, enzymes, and haemoglobin (the oxygen-carrying pigment of red blood cells). An adequate intake of protein is necessary for growth and repair of body cells, the normal functioning of muscles, transmission of nerve impulses and immunity. Protein can also be used as energy, but is not the body s preferred energy source, so this occurs only when the amount of carbohydrate and fats consumed are insufficient. Main sources of protein Consuming a reasonable variety of protein-containing foods, as part of a diet which includes enough calories overall, is all that is needed to ensure a healthy protein intake. 1 Main sources of protein in a vegan diet include: Pulses: peas, beans (aduki beans, blackeye beans, chickpeas (and chickpea flour), kidney beans), lentils, soya foods (tofu, tempeh, soya mince, soya milk) Nuts: cashews, almonds, peanuts, pistachios (note that some nuts such as chestnuts and macadamias are poor sources of protein and others such as Brazil nuts, walnuts, pine nuts, pecan nuts and hazel nuts are mediocre sources) Seeds: pumpkin, sunflower, sesame Grains: wheat, oats, buckwheat, millet, quinoa, amaranth, pasta, bread, seitan (wheat protein) (note that rice is a relatively poor source of protein) 1

2 Cereals contribute around 22% of protein in average UK diets (mainly from pasta, rice, bread and wholegrain breakfast cereals). 2 Most readily available plant-based foods provide adequate amounts of protein. However, there are few plant foods contain relatively low amounts of protein, such as most fruits and some root vegetables. 3 Including protein in meals A balanced main meal should include a protein element. As a general rule, to ensure that a meal is balanced, check that it includes carbohydrate, protein and vegetable ingredients. Remember to avoid the pitfall of regularly serving main meals which consist just of carbohydrates and vegetables and no protein-rich ingredients (e.g. pasta and tomato sauce or vegetables, vegetable stir fry and noodles/rice, vegetable chilli or curry and rice, salads without a protein or carbohydrate element). This can be as easy as including a handful of nuts or some tinned beans with a pasta and sauce dish, or adding tofu pieces, cashew nuts or pumpkin seeds to a stir fry. If you need more detail on incorporating protein ingredients into meals, see here. Vegan athletes A well-planned vegan diet can supply all the protein and other nutrients required by athletes. Currently, there is no strong body of evidence suggesting that healthy adults who undertake resistance training require unique protein recommendations, so for most vegans who keep fit with regular exercise, a daily consumption of 0.9 grams of protein per kilogram of body weight is plenty. However, strength athletes consuming any diet, including a vegan diet require extra protein; therefore, vegans are advised to consume 1.3 to 1.9 g/kg/day, especially during the stage when they are adding muscle tissue 2,3. For those who wish to supplement their dietary intake using protein powders for convenience, there are various vegan-suitable protein powders available. These are often made from soya, hemp, pea or nut protein. How much do I need? The UK Reference Nutrient Intakes (RNI) for protein are approximately 45-55g a day 5 for adults. 2

3 The UK RNI is calculated based on a requirement for 0.75g protein per 1kg bodyweight per day. 5 Protein requirements for vegan diets are slightly higher to allow for small differences in digestibility between plant and animal protein; round up to 1g of protein per 1kg of your normal, healthy bodyweight. As a guide, here are some common plant foods and the approximate amounts of protein per serving they contain (with serving size in brackets). 1 serving = 75g of protein Seitan (100g) 1 serving = 20g protein Tofu (100g-200g depending on brand) Tempeh (100g) 2 soya/wheat-based veggie sausages (depending on brand) Soya mince (60g, depending on brand) 1 serving = 10g protein 2 slices wholemeal bread Wholemeal pasta (75g dry weight) Baked beans (200g, tinned) Red lentils (40g dry weight) Green lentils (40g dry weight) Kidney beans (145g, tinned and drained) 5-6 falafel Oats (60g dry weight) Chickpeas (140g, tinned and drained) 1 serving = 7.5g protein Quinoa (50g dry weight) Amaranth (50g dry weight) Buckwheat (60g dry weight) Millet (70g dry weight) 1 serving = 5g protein Brown rice (75g dry weight) Pumpkin seeds (20g) Cashew nuts (25g) Peanuts (20g) Peas (frozen) (70g) Sunflower seeds (25g) 3

4 Peanut butter (20g) Houmous (70g) More is not better Average UK diets may include more protein than is optimal for good health: on average men consume 88.4g and women 66.3g. 2 Well-planned vegan diets have the advantage of easily providing sufficient protein without resulting in excessive intakes which may be detrimental to health. 3 Excess protein consumption offers no obvious benefits, as the body cannot store surplus protein. 1 The ill-effects of excess protein are not yet fully understood but there is some indication that kidney function (particularly in older people and those with existing kidney problems) and bone density may be adversely affected by excessive protein intakes. 1 Protein terminology explained Amino acids Proteins are comprised of 21 amino acids, the building blocks which make up proteins. This includes 8 (for adults) or 10 (for infants) amino acids which must be obtained directly from food - called essential amino acids. The remaining amino acids are either non-essential, which can easily be produced by the body, or conditionally essential, which can usually be made by the body but may be required in the diet under certain circumstances (such as during illness). These are essential: Isoleucine, Leucine, Valine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Histidine, Selenocysteine. Non-essential: Alanine, Aspartic acid, Asparagine, Glutamic acid, Serine. Conditionally essential: Arginine, Cysteine, Glutamine, Glycine, Proline, Tyrosine. A diet comprising a variety of plant protein sources will include all the essential amino acids. 1 What are complete proteins? 4

5 A food which contains all the essential amino acids in sufficient quantities to meet the body s needs is referred to as a complete protein. A few plant-based foods, such as soya, buckwheat, quinoa and amaranth, are complete proteins. Most plant-based foods do not contain sufficient quantities of all the essential amino acids; instead, the full range of amino acids is provided in the diet across a variety of different foods. It is not necessary to eat complete proteins in order to obtain all the essential amino acids. Protein combining You may still encounter the concept of protein combining, particularly in older literature. This was a concept from some years ago (devised by the author of a book called Diet for a Small Planet published in the 1970s) that it was necessary to eat all the essential amino acids together in the same meal, by eating certain types of foods together such as rice and beans. It is now widely understood that this is not required - a reasonable variety of protein foods consumed over the course of a day is sufficient. 4 References 1. Davis, B, Vesanto, M, [2014] Becoming Vegan: Comprehensive Edition, Summertown, TN, The Book Publishing Company. 2. American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. A Am Diet Assoc. 2009;109(3) Fuhrman J et al. Fueling the Vegetarian (Vegan) Athlete. Curr Sports Med Rep. 2010; 9(4): Mangels R, Messina V, Messina M [2011]. The dietitian's guide to vegetarian diets: issues and applications. 3rd ed. Sudbury, MA: Jones and Bartlett Learning. 5. Department of Health Dietary Reference Values for Food Energy and Nutrients for the United Kingdom London: HMSO; Food Standards Agency McCance and Widdowson s The Composition of Foods (Sixth edition) Cambridge: Royal Society of Chemistry;