April 7, 2025

Metabolism & Protein Needs As We Age

I hear it all the time – from clients, friends and family members: “My metabolism just isn’t what it used to be”. Or, “I used to be able to eat whatever I wanted, and now just looking at food makes me gain weight!”.

It’s true that weight-loss – or even maintaining a healthy weight – becomes more difficult as we age. But is our metabolism really just “slowing down”, or could there be other factors at play?

For post-menopausal women, hormones definitely play a role; Some experts even believe that the weight gain that results from the menopausal hormonal shift is actually a protective mechanism, as it cushions our bones from potential falls (post-menopausal women are also more prone to osteoporosis), and bolsters our fat stores for better chances of survival during illness or injury.

Natural design aside, we do know that lifestyle changes (such as decreased physical activity) can also contribute to weight gain as we age. And it’s not just post-menopausal women; Emerging research* suggests that, if we do nothing to proactively maintain it, muscle mass decreases by approximately 3-8% per decade after the age of 30. And women can lose up to 30-50% of their muscle mass after age 40.

Since muscle tissue is more metabolically active than fat tissue, meaning it requires more energy (calories) to function, this would certainly result in the down-regulation of metabolism and subsequent weight gain.

How do we stop this from happening?

Regular weight-bearing and strength-training exercise is obviously essential. But another important piece to the puzzle is the fact that, as we age, our body requires more protein to initiate muscle protein synthesis (the process of turning dietary protein into muscle mass). Specifically, studies show* that middle-aged women need approximately 10-15 grams more protein per dose to achieve the same level of muscle protein synthesis observed in younger adults.

Sadly, no governmental recommendations account for this. Many qualified health practitioners agree that the current R.D.A. of 0.8 grams per kilogram of body weight is grossly insufficient; not only is this the bare minimum to prevent dietary deficiency for the average sedentary adult (meaning it’s enough to keep you alive if you are doing virtually nothing); the guidelines are also the same no matter how old you are. Even worse, research shows* that more than 40% of women aren’t even meeting the R.D.A.

This brings to light the reality that the majority of people (women especially) are undereating protein, which, as we now know, is a key contributor to decreased muscle mass and lowered metabolic function as we age.

So how much protein do we actually need?

Ahh the billion-dollar question (no, really – protein-fortified drinks, bars, chips, cereal, pasta, bread and even candy is now a billion-dollar industry). The actual numbers come in a wide range, depending who you ask, but the strongest evidence-based* literature suggests that we need between 1.2 and 2 grams per kilogram of body weight just to maintain muscle mass as we age. This is 50% higher than the current government R.D.A. Keep in mind: all nutrient needs can vary greatly from one person to another, and your protein requirement will be higher if you are active, or if you are recovering from injury.

I’ll be the first to admit that it can sometimes seem impossible to choke down enough protein to meet even the lowest recommendations without feeling bloated and constipated. Personally, I believe our bodies contain more wisdom than any ab-fluencer or even peer-reviewed study can provide. At the end of the day, it’s less important to obsess over the numbers than it is to simply lead with protein-forward meals, and to prioritize complete (meaning they contain all of the essential amino acids), bio-available protein sources.

By listening to our bodies, eating a balanced, whole-foods diet, and bringing a little intention to our meals, I believe it’s perfectly attainable to achieve a protein intake that’s optimal for our own unique system and season of life. Here are a few simple tips to get you started:

Aim to start your day with 30 grams of protein. You can easily achieve this with any of the following breakfast ideas:

3 eggs + 3 slices turkey + avocado and/or your favourite fruit

A smoothie with 1 scoop of protein powder + 1 Tbsp peanut butter or ¼ cup Greek yogurt

2 chicken sausages + ½ cup Greek yogurt + your favourite fruit

Looking for an easy hack? Boost your morning protein intake by a whole 10 grams just by starting your day with a cup of bone broth!

Be sure to include a protein source with every meal and snack. This can be anything from eggs to cottage cheese, yogurt, nuts and seeds, nut butter, canned tuna, smoked salmon, beef jerky, edamame or hummus.

Prioritize complete, bioavailable proteins, which provide more efficient muscle protein synthesis. These include foods such as beef, chicken, fish, eggs, dairy and quinoa. Pro Tip: Many plant-based protein sources are incomplete (meaning they do not contain all 9 essential amino acids), but you can complete them by combining any grain and any legume (ex. Hummus and pita, rice and beans, toast with peanut butter, etc.)