How Much Protein to Eat?

How much is too much and too little?

For those of you familiar with the  “My Big Fat Greek Wedding” series know that the father in the movie prides himself on the derivation of English words from Greek beginnings. Did I know that the origin of the word “protein” comes from the Greek word protos, which means “first?” No, I did not! Protein has been in the news A LOT lately but for today’s topic, I wanted to look at protein recommendations for the aging population. 

Let’s start with my favorite subject—science! Proteins are one of the macronutrients (the other two are carbohydrates and fat). These are often referred to as “macros” and are the only nutrients that provide calories and directly fuel our bodies. Protein is made up of amino acids, and play a role in metabolism, hormone synthesis, immune systems, and in tissue repair and restoration. While it provides a small amount of fuel during exercise, it is vital in repairing damaged muscles in the recovery phase. 

Next, let’s review the current recommendations for proteins—AKA “RDAs.”  Established by the Institute of Medicine (of the National Academies of Sciences, Engineering, and Medicine), the Recommended Dietary Allowance (RDA) is an average of the daily level of intake that sufficiently meets the nutrient requirements of nearly all (97–98%) healthy individuals. The RDAs are set for all nutrients and are based on scientific evidence and expert review. They vary depending on age and sex, and are used in food labeling to cite nutritional recommendations and/or dietary guidelines. They provide a guideline for nutrient intake, but are not a strict requirement.

The RDA for protein is 0.8 grams of protein per kilogram of body weight—or 0.36 grams per pound. While athletes may require a higher level of protein than the RDA, research shows that intakes above 1.6 g/kg don’t provide additional benefits for muscle protein synthesis in non-athletes. 

We know that activity affects protein requirements, but what about age?  I always tell my patients that as we age, so do our vital organs in the body! Our systems just don’t work as well as they used to. New evidence demonstrates that older adults are less efficient in metabolizing protein and that their needs are different than the RDA values.

Internationally, the European Union Geriatric Medicine Society has developed the PROT-AGE Study Group. After reviewing science based evidence regarding loss of lean body mass/muscle mass associated with aging (sarcopenia), this group has recommended an average daily intake of 1.0–1.2 g protein per kilogram (kg) body weight per day for older adults. Studies find that around 1g/kg/day helps to support lean tissue development as well as promote and maintain bone and immune health in this age group. 

The PROT-AGE study group also looked at exercise. A higher protein intake (≥ 1.2 g/kg body weight/d) is advised for those in this age group who engage in endurance (cardio) and resistance (strength training) exercises. 

The study group also defined protein needs for older adults who have acute or chronic diseases. They need even more dietary protein (1.2-1.5 g/kg body weight/day). It’s important to consider that anyone with severe kidney disease is an exception to this recommendation; these individuals usually need to limit protein intake. People with diabetes should also be cautious. Always check with your health care professional before making any major changes to your diet. 

So does it matter how you eat protein throughout the day? Yes, it does. It’s best to distribute your allotment evenly at breakfast, lunch, dinner and snacks. One study showed that the maximum of protein that can be effectively utilized at a single meal is 30 grams (equivalent to about 4 ounces of meat). Any more than this does not further enhance the stimulation of muscle protein synthesis in adults aged 51 and older. Therefore, balancing protein intake throughout the day will help to ensure that protein intake is maximized.

Consuming protein after exercise (within 3 hours) is also beneficial for absorption. The PROT-AGE Study Group notes that older adults should consider taking 20 g of protein after exercise sessions “as muscle sensitivity to amino acids may be increased after exercise.”

Some social media posts are suggesting three times the RDA amount; that's almost 2.2 grams of protein/kg. These recommendations are not evidence-based. Take note that excessive intake of protein has medical repercussions in the body. Too much protein can increase the risk of developing kidney stones or gout. Also, a high protein diet that contains lots of red meat and higher amounts of saturated fat might lead to a higher risk of heart disease and colon cancer.

Ultimately, it’s all about the balance of your diet that counts. Spreading your food out between three meals and a few snacks helps to keep you full, as well fuel your body for busy days!  Work with a registered dietitian who can help you plan out meals that work for you and your own schedule.

In Good Health,

Sophie