Protein, along with carbohydrate and fat, is considered a “macronutrient”, a source of energy for the body. It is important for building and repairing muscles and tissues, growth and development and an essential part of hormones, enzymes and antibodies. Consuming protein with a meal or snack also helps you feel full. In Canada, the Dietary Reference Intake (DRI) for adults is 0.8 grams of protein per kg of body weight, or about 10-35% of your total caloric intake. For example, an adult who weighs 85 kg, would need about 68 grams of protein per day. The recommendations for protein are higher for children, adolescents, pregnant/breastfeeding women, athletes and older adults. Those with health conditions like advanced kidney disease, may need to consume less protein.
A diet that is too low in protein can affect growth, immunity and result in loss of lean muscle mass, especially if combined with a lower calorie intake. People that need to be on a protein restricted diet due to a specific health condition should ensure that they are getting enough calories/nutrients from other foods to help them stay healthy and maintain their weight. Protein/calorie restriction as a way to lose weight can lead to loss of lean muscle mass, a slower metabolism and an increase in appetite that comes from not feeling full. This approach is not effective for long term weight loss and also increases the risk of developing an eating disorder.
In contrast, when more protein is consumed than needed, some parts are stored as fat and the body disposes of the rest of it through our urine. Although athletes may require extra protein, it may not be as much as they think. It is their overall calorie intake that is important. They need to make sure they are consuming adequate carbohydrate and fat as well so that the protein they consume is used mostly for muscle and tissue growth and repair instead of for energy.
In older people, an increase in protein intake in addition to resistance exercise can help to maintain muscle mass, strength and function which is important for balance and prevention of falls. Preserving lean muscle mass is also key for improving metabolism and minimizing the weight gain that often occurs with aging.
Some people may choose to follow a high protein/fat diet such as the “keto diet”, for weight loss. The calorie restriction resulting from the significant reduction in carbohydrate along with a decrease in appetite may promote weight loss initially. Studies show that weight loss on these diets is similar to other less restrictive dietary interventions after one year. (1) This may be in part because many people find it difficult to sustain this way of eating long-term. A diet that focuses on one particular food group may also put you at risk of deficiency of nutrients important for maintaining good health.
The new Canada’s Food Guide recommends that in order to maintain good health, you should be getting “balanced” meals with ¼ of your plate coming from protein foods, ¼ from whole grains and ½ from fruits and vegetables. It also recommends choosing protein foods that come from plant sources more often. Animal sources of protein contain saturated fat, a known risk factor for cardiovascular disease. Although some saturated fat in the diet is beneficial, too much is not good. Animal sources of protein include meat, poultry, eggs and dairy products such as milk, yogurt and cheese. Choosing lean cuts of meat, removing the skin from poultry, using lower fat dairy products and cooking with less fat, can help reduce the amount of fat in these foods. Limiting protein foods that are processed such as deli meats, wieners and sausages is also recommended. Fatty fish such as salmon, mackerel, herring and trout and plant proteins contain healthy fats, and should be consumed more often. Plant proteins include legumes, lentils, nuts, seeds, nut butters, tofu and other soy products. Processed plant protein foods such as “plant-based” burgers, wieners and nuggets, can contain unhealthy fats and excess sodium and should be consumed in moderation.
Including protein with meals and snacks not only ensures that you meet your needs but also helps satisfy your hunger. Here are some ways that you can add protein to your diet:
Have eggs or peanut butter with multigrain toast
Add ground flax seed or slivered almonds to your oatmeal
Use Greek yogurt to make a parfait with muesli and berries
Stuff a pita with hummus and chickpeas
Add beans or chick peas to a grain-based salad
Include tuna or salmon in a wrap
Top a salad with grilled chicken or nuts/seeds
Add chicken, beans or lentils to your soups
Grill a Salmon fillet and serve with quinoa and a vegetable
Make a stir fry using tofu or grilled chicken
Add beans to a casserole, stew or pasta dish
Use eggs to make an omelette or frittata
Almond butter with apple slices
Lower fat cheese and whole grain crackers
Hummus and carrot sticks
Lower fat cottage cheese with fruit
Tuna on whole grain melba toast
If you are not sure if you are getting enough protein in your diet, or too much, contact Cheryl Corry, Registered Dietitian for a nutrition assessment and advice about how you can improve your protein intake.
Eat Well, Live Well
1. Bueno NB et al. B J Nutr, 2013 Oct; 1 10(7): 1178-87