Are you getting enough protein in your diet?
Protein is not just the building block of our bodies, but also essential for growth and repair, cell to cell communication, immunity, and a thousand (or more) other functions.
It’s also a source of energy, and a very tasty one. But how do you know if you’re getting enough?
Optimal protein intake depends on our age, lifestyle, and goals, and is therefore a personal thing. Whether you’re interested in increasing muscle mass and strength, losing weight, ageing well, or just living your healthiest you, read on.
Optimal protein intake
The current recommended dietary intake (RDI) of protein is 0.8g per kg of bodyweight per day. This rather modest target might be enough to prevent protein deficiency in an average person, but it’s hardly optimal.
For context, a person weighing 75kg would meet that target with one small steak per day. But that simply wouldn’t be enough for someone trying to gain muscle, lose weight, or if they’re ageing.
In fact, an increasing number of experts suggest that the RDI should be doubled (which would be roughly 25% of total daily calorie intake), and some think it should be even higher!
It’s important to consider not only the amount of protein intake, but also the sources. A variety of both plant and lean animal proteins are recommended to fulfil your optimal protein requirements.
Get more out of protein
Protein intake for athletes
Protein intake is essential for muscle repair and synthesis, reducing muscle soreness, and boosting glycogen storage (when coingested with carbohydrate post exercise) . You won’t find many athletes who need convincing about the benefits of more protein!
However, optimal protein intake for athletes will depend on the specific sport or training goals, and recommendations can vary between 1.4g to 3g per kg of bodyweight per day. For example, strength training will have different protein requirements than endurance training; and beginners tend to need more protein than trained athletes.
Vegans, vegetarians, and myth busting
An often-heard statement is that vegetarians and vegans do not get enough protein in their diet compared to omnivores.
Animal sources of protein are “complete”, meaning they contain all nine essential amino acids (EAAs), whereas most plant sources are “incomplete” (with the exception of quinoa, amaranth, buckwheat, hemp seeds, chia seeds, and soy products such as tofu, tempeh, edamame). There are also classic pairings of plant proteins that provide a complete set of all EAAs such as rice & beans.
However, you can get all the essential amino acids from plant sources as long as you eat a variety of them throughout the day.
Vegans may require a higher protein intake, however (perhaps up to 10% more), because some plant proteins are harder to digest than animal and dairy protein. So people following a plant-based diet should ensure every meal is packed with a variety of high protein sources such as beans, legumes, chickpeas, soy, nuts and seeds.
If you are vegan and an athlete, a plant-based diet can easily provide all the protein you need, provided it comes from a variety of sources. However, it may be worth making sure you are getting enough leucine in your diet; this essential amino acid is crucial for muscle protein synthesis and tends to be lower in plant sources than animal sources.
The power of protein
Protein can help you lose weight
Consuming extra protein can aid weight loss in a number of different ways:
Protein makes you feel full
Eating protein increases the hormones that make you feel full, while reducing hormones that make you feel hungry. Including good quality sources of protein in each meal can help reduce those mid-afternoon cravings or overeating at dinner, which can lead to you losing weight.
Protein boosts your metabolism
Protein has a much higher ‘thermic effect of food’ (the energy required for your body to digest and absorb the food) compared to carbohydrates or fat – in fact your body burns up to 30% more calories digesting protein than it does digesting carbs or fat. This energy-burn boosts your metabolism.
Protein maintains muscle mass
Your muscles account for a quarter of your body’s metabolic activity. A decent intake of protein (combined with resistance exercise) will help boost your metabolic rate by increasing muscle mass and reducing fat mass.
Protein intake and getting older
You don’t need to be “old” to start thinking about how age affects your protein requirements.
As we age we lose muscle mass, in fact we begin to lose 0.5%-1% per year from the age of around 45. This age-related muscle decline is called sarcopenia, and is linked to poor health and loss of independence, and is inversely related to longevity. Post-menopausal women especially experience a reduction in muscle mass and a shift in insulin sensitivity due to a decline in oestrogen.
The good news is sarcopenia can be mitigated by increased daily protein intake and with load bearing exercise. Ensuring protein intake is evenly distributed throughout the day also helps.
Are high protein diets dangerous?
For the average healthy adult, there are no adverse effects of increasing dietary protein intake, so long as it is not at the expense of healthy fats and adequate dietary fibre. However, a high protein diet is not recommended for those with pre-existing kidney conditions.
To wrap up
Optimal protein intake may be a wee bit more than you think, and is dependent on age, lifestyle, activity level and goals. Variety is the key, particularly if you are following a plant-based diet. Guidance from a qualified nutritionist will be helpful in determining your own, personalised, protein requirements for optimal health and performance.
