Protein is important all year round for building and repairing tissues, maintaining muscle mass, producing hormones and supporting immune health. In winter, that’s more important than ever as we spend more time indoors, getting less exercise and greater exposure to flu and other infections.
Protein for better immune function
Protein plays a key role in immunity: amino acids are needed for the synthesis of immune proteins, including cytokines and antibodies such as killer T cells that fight infection and prevent you getting sick or help you recover faster, says Gauteng sport and exercise physiologist Brad Phillips.
Protein for fewer cold-weather cravings
It is also important for managing weight. In winter, your body needs to use slightly more energy to keep warm, and it’s common to feel hungrier and pick up a kilo or two, says Marie MacGregor, a registered dietitian with the Sports Science Institute of South Africa. “Protein and carbohydrates have the same calories per gram, but protein is more satiating. Both protein and carbohydrates have fewer calories than fat, and all three are needed, in balance.” A 2020 review in the journal Physiology & Behavior found protein lowers levels of ghrelin, the ‘hunger hormone’, and raises levels of hormones responsible for signals of fullness.
Protein to boost metabolism
In addition, protein helps boost metabolism and fat burning, as it has a modestly higher thermic effect (the use of calories to digest nutrients) than carbohydrates and fats, contributing to a higher basal metabolic rate (the number of calories you use for basic functions such as breathing).
Protein for fitness and recovery
Protein is also important for recovery after a workout, says MacGregor. It promotes muscle protein synthesis, increasing muscle mass during strength training and helping prevent injury and muscle loss during weight loss. A 2022 review in the Journal of Cachexia, Sarcopenia and Muscle found it also improved bone density (plant protein was less effective than animal).
Protein intake plays a role in overall fitness, and can help you keep fit as you grow older, reducing age-related muscle deterioration and preventing age-related sarcopenia (progressive loss of muscle mass, strength and function), but speak to your healthcare provider first, especially if you have kidney disease, says Phillips.
How much protein do you really need?
Baseline protein requirements are 0.8g of protein per kilogram of body weight – 56g for an average 70kg male and 46g for an average 60kg female, says MacGregor. However, this will vary with age, how much exercise you do and your overall health. Be aware of signs of deficiency: brittle nails, thinning hair, slow-healing cuts and bruises, feelings of weakness, increased hunger, loss of muscle mass and higher risk of bone fracture.
How to get more protein in winter
Protein should be part of a balanced diet and come from a variety of sources – lean meats and fish, eggs and dairy products, beans, peas and lentils, seeds and nuts, and soy products such as tofu and tempeh. “Getting a little extra protein in winter can be as simple as swapping cereal for eggs at breakfast, adding cottage cheese to your avocado sandwich, adding lentils, beans or chickpeas to your soups and stews, and having yoghurt and nuts as a mid-morning snack,” says MacGregor.
You can also try winter smoothies made with warming spices (cinnamon, ginger, turmeric, nutmeg). Use hot water, warm milk or chai tea as a base, with bananas, apples, carrots, zucchini, or kale. Add nuts, seeds, yoghurt or protein powder for a protein boost.
When exercising hard, recovery nutrition for muscle repair and immunity should be around 20-30g of protein consumed along with carbohydrate, says MacGregor. This should preferably be within half an hour of training, though recent research suggests total daily protein may be more important than timing. Think a two or three-egg omelette or scrambled tofu with spinach and a slice or two of wholewheat bread; grilled salmon on brown rice with winter herbs; or roast chicken with baked sweet potato and broccoli.
“If you are concerned that you are not meeting protein targets in your diet, speak to a registered dietitian who can optimise your diet and make recommendations for supplementation if needed, such as whey, casein and soy,” MacGregor says.
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