Pumping Up Protein for Midlife Health

The penchant for protein requires perspective. Here's a protein primer.

Why You Need Protein

The protein in food provides amino acids necessary to keep you going and to support your overall health. During digestion, the body breaks down protein into individual amino acids and reassembles them into cells, enzymes, hormones, and other compounds that sustain life.

Protein provides four calories per gram, as many as carbohydrate and about half as much as fat. In a pinch, protein can be used for its energy, but that’s not ideal. A balanced eating plan with adequate carbohydrate, the body’s preferred fuel source, spares protein from being used for its calories and allows it to complete its other tasks, including preserving and producing skeletal muscle mass, which I wrote about in detail here. 

Protein’s Role in Weight Control

Protein takes more time to digest than carbohydrate, adding to eating satisfaction and possibly curbing excess calorie consumption, and it may play a role in easier weight control in two ways.

Higher-protein meals stimulate the release of glucagon-like peptide 1 (GLP-1), a hormone that slows the speed at which food leaves the stomach, creating a longer-lasting feeling of fullness.  Evidence suggests that consuming protein and calcium simultaneously (think: dairy foods) enhances the secretion of GLP-1. Semaglutide, the drug whose brand names include Ozempic and Wegovy, mimic the effects of GLP-1.

Of all the calorie-containing nutrients, protein possesses the greatest thermic effect of food (TEF).  That means the body uses more energy to digest and process protein than it does for carbohydrate or fat. Protein’s higher TEF may provide a slight calorie-burning edge that can help you lose or maintain body weight.

Photo by i yunmai on Unsplash

How Much Protein Do You Need Every Day?

Protein requirements are a hot topic and there’s no shortage of misinformation on the internet about how much protein you require. One thing is certain, however. Most protein researchers consider the U.S. Recommended Dietary Allowance (RDA) for protein (0.8 grams per kilogram of body weight or 0.36 grams per pound) too low, especially for people over the age of 50 and for weight loss.

The RDA is the minimum amount of protein that prevents malnutrition. However, it makes no allowances for aging or menopause, both of which contribute to muscle tissue loss.  Muscle makes up the majority of lean tissue and comprises 30% to 40% of your entire body mass. Adequate protein, along with regular resistance training, is necessary to protect against muscle loss, especially with age. A meta-analysis of protein consumption studies published in Advances in Nutrition found that protein intakes greater than the RDA helped preserve lean mass compared to consuming the RDA, while a review published in Advances in Nutrition proposes that older people need about 50% more protein than the current recommendation.  

Protein is about more than making muscle, though. It’s also responsible for supporting your bones as well as the immune system, the integrity of your skin and gums, and for wound healing. These functions are particularly important as you get older.

According to the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO), women over 50 should get 1 to 1.2 grams of protein per kilogram (kg) every day for muscle as well as bone health.  Other research corroborates this suggestion, including recommendations from the PROT_AGE study group, which contends that women and men over the age of 65 need 1 to 1.2 grams of protein per kg daily, and possibly more if they are physically active.

When you’re weight loss is the goal and you’re in a calorie deficit, it’s possible to lose muscle tissue along with body fat. Adequate protein protects against that. A Nutrition & Metabolism study found that eating fewer calories and more protein helped people retain more of their lean mass. Middle-aged men and women in the study cut 500 calories from their eating plans. One group ate twice the U.S. RDA for protein (1.6 grams protein per kg per day or 0.72 grams per pound) and the other group consumed the RDA for protein. Those eating more protein lost more body fat and retained more lean tissue over a year’s time than people consuming the RDA for protein.  In a 12-week trial published in The American Journal of Clinical Nutrition, 100 women with overweight or obesity who ate more protein lost more body fat than those on a lower-protein eating plan.

In the past, there was concern about higher protein intakes increasing the risk for kidney disease or osteoporosis, but research doesn’t support this. In fact, protein is necessary for bone health and is particularly beneficial to bones when you also consume 1,200 milligrams of calcium daily after age 51. If you have diabetes or kidney disease, work with a registered dietitian nutritionist (RDN) to determine how much protein is right for you. 

How to Figure Out Your Protein Needs

The most accurate way to determine daily protein needs is based on body weight.

If you’re new to eating more protein, start by including at least 1 to 1.2 grams of protein for every kg of body weight, which amounts to 0.45 to 0.54 grams of protein for every pound you weigh.   

If weight loss is your goal, or you’re very physically active, you could eat as much as 1.6 grams of protein for every kg (0.72 grams per pound) of body weight daily. Women with obesity should use their adjusted body weight to calculate protein needs.

Here are some examples of how to calculate protein needs.

Example #1: Weight Maintenance

Body weight: 150 pounds (68 kg)

Goal protein intake per day: 0.45 to 0.54 grams of protein per pound (1 to 1.2 grams of protein per kg current body weight)

150 X 0.45 grams protein = 68 grams protein per day

150 X 0.54 grams protein = 81 grams protein per day

Result: The range of protein intake for a 150-pound woman is 68 to 81 grams per day.

Example #2: Weight Loss

First, subtract your goal, or ideal, weight from your current body weight. Now, multiply that number by 0.25.  That’s the number of pounds to add back to your goal weight in order to determine daily protein needs. Here’s an example.

Current body weight: 200 pounds (91 kg)

Goal weight: 150 pounds (68 kg)

Goal protein intake per day: 0.45 to 0.54 grams of protein per pound (1 to 1.2 grams of protein per kg body weight)

200 pounds – 150 pounds = 50 pounds

50 pounds X 0.25 = 12.5 pounds

150 pounds + 12.5 pounds = 162.5 pounds (74 kg); this is your adjusted body weight

Now, calculate daily protein needs using your adjusted body weight:

162.5 X 0.45 grams protein = 73 grams protein per day

162.5 X 0.54 grams protein = 88 grams protein per day

Result: Include 73 to 88 grams protein per day.

Example #3: Weight Loss with Higher Protein Level

Goal protein intake: 0.72 grams of protein per pound of adjusted body weight (1.6 grams of protein per kg of adjusted body weight)

Use adjusted body weight from Example #2 (162.5 pounds/74 kg):

162.5 X 0.72 grams protein = 117 grams protein per day

Result: Consume 117 grams of protein per day

There’s little doubt that midlife women need more protein than the RDA provides, but it must be part of a balanced diet with the right amount of calories from protein, fat, and carbohydrate to maintain or lose weight. Protein provides calories, and simply adding more protein to your current eating plan can tack on extra energy that could result in weight gain. If you want to increase protein, you must consider how it fits into your overall calorie needs. You will probably need to cut back on carbohydrate and fat, especially for weight loss, to make room for more protein.  

Animal or Plant Protein: Which is Better?

Now that you know how much protein to eat, what type of protein should you choose? Food protein is made up of 20 amino acids. While every amino acid is necessary for life, the body cannot produce all of them. That’s where animal and plant foods come in.

Your body can make all but nine of the 20 amino acids; those nine are often called essential or indispensable amino acids. You don’t stockpile amino acids the way you do carbohydrate (as glycogen in the liver and muscles) and fat, so you must eat them every day.

Animal foods, such as meat, poultry, eggs, dairy, and seafood, supply all of the amino acids that the body doesn’t make. With the exception of soy foods, pistachios, quinoa, and buckwheat, nearly all plant foods lack sufficient amounts of one or more essential amino acids. 

Consistently coming up short on essential amino acids can limit muscle mass and strength and have other negative effects on overall health. That’s not to say it’s impossible to meet the RDA for protein and satisfy amino acid requirements by eating plant foods only. On the contrary. Research shows that people trying to gain muscle mass can do so on a completely plant-based eating plan as long as they choose their protein sources carefully and eat enough of them. Plant-based eating plans may help with weight loss, lower blood pressure, reduce blood cholesterol levels, and help to keep type 2 diabetes at bay.

What is Leucine?

Though adequate quantities of animal or plant foods, or a combination, can provide the required essential amino acids, animal proteins provide more leucine per serving.  Leucine is responsible for triggering the muscle-making process, and it’s possible that older adults require more of this single amino acid to stimulate muscle tissue production.

Leucine may turn on muscle-making but the body requires all of the amino acids for the effect to persist. In a British Journal of Nutrition study, consuming seven grams a day of leucine along with a higher total protein intake (1.25 grams of protein per kg per day ) was linked to greater lean body mass over a period of six years compared to eating less than seven grams of leucine daily.

Foods with Protein and Leucine

Use this chart to help you get the protein and leucine you need in your eating plan. For a more complete list, see The Menopause Diet Plan, A Natural Guide to Managing Hormones, Health, and Happiness, the book I wrote with Hillary Wright, MEd, RDN.

Food                                                                        Protein (grams)      Leucine (grams)

Chicken breast, boneless, skinless, 4 ounces, cooked                36                       2.70

Tuna, canned, drained, 4 ounces                                         33                      1.70

Tempeh, cooked, 4 ounces                                                  26                      0.80

Yogurt, Greek, plain, non-fat, 1 cup                                              22                      2.2

Beef, ground, 95% lean, 4 ounces, cooked                                   25                    2

Tofu, 4 ounces, firm                                                             13                       0.9

Cottage cheese, low-fat, ½ cup                                            12                        1.4

Lentils, ½ cup, cooked                                                          9                        0.65

Black beans, canned, drained, ½ cup                                           7                        0.60

Egg, 1 large                                                                 6                         0.55

(Source: United States Department of Agriculture. Agricultural Research Service. USDA Food Composition Databases) 

When Should You Eat Protein?

You’ve probably heard the advice to include at least 25 to 30 grams of protein at every meal to maximize muscle tissue production. A 2023 randomized controlled study published in Cell Reports Medicine challenges that notion, suggesting that eating enough protein during the day is more important than when you eat where muscle is concerned.

This study is particularly good news for breakfast eaters who struggle to include about one-third of their daily protein quota at the morning meal (I’m with you on that!). Yet, I still recommend distributing protein as evenly as possible throughout the day, including in snacks. As I mentioned earlier, protein provides eating satisfaction to help you feel fuller for longer and avoid overeating.

Questions about protein? Let me know in the comments!