How Much Protein Can Your Body Use from One Meal?

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Steak is a high protein meal

How much protein can your body digest and use at a time? If you you eat the right amount of protein at every meal you’ll supposedly hit the sweet spot – maximum muscle growth and satiety (fullness) without wasting food or money. General guidelines based on short term trials and one cross-sectional study suggest adults need regular meals including 25 – 45 grams of protein per meal to maintain or build muscle mass and maximum strength (1, 2, 3). However, it is possible that more protein per meal may be beneficial in some instances while the per meal amount might not matter very much in others. Your body can and will digest all of the protein you eat in a sitting (it might take a while) and it doesn’t just discard any excess that isn’t used to build structures in the body.

In this article I’ll cover:

  1. Why should we focus on a “per meal” dose of protein?
  2. What happens to “leftover” protein;
  3. What influences protein requirements;
  4. How you can estimate your protein needs.

Does the Amount of Protein Per Meal Matter?

In a really cool study conducted by well-known protein scientists, the minimum amount of protein per meal found to maximally spike muscle growth was 0.11 grams per lb. of body weight in younger adults and 0.18 grams per lb. of body weight in older adults (over 71 years of age) (2). Older adults need more protein due to a decline in muscle response to protein intake that occurs with age. In addition to a minimum, there is an upper limit of protein intake; anything beyond this threshold dose will not be used to build muscle. For example, one study examined 4 ounces of beef containing 30 grams of protein compared to 12 ounces of beef containing 90 grams of protein. The larger serving did not lead to a greater increase in acute muscle protein synthesis compared to the 4 ounce serving (4). So now we know we need some protein, but not 90 grams in one sitting. However, we still don’t know what the minimum upper limit is, beyond which higher intakes do not lead to increases in muscle mass or muscle functioning over time (5).

More evidence for a per meal dose came from a short-term study that found an even pattern of high quality protein at each meal (30 grams per meal; 1.2 g/kg for the day) as opposed to a skewed pattern (10 grams at breakfast, 15 g lunch and 65 g at dinner; 1.2 g/kg for the day) may be best for maximally stimulating muscle building in young adults (1).

Despite the evidence in favor of an even distribution of protein intake throughout the day, a short-term study in older, resistance trained adults given 2x the RDA – 0.68 grams of protein per lb. bodyweight (1.5 grams per kg) per day in an uneven or even pattern (see chart at the end of this article) or the RDA of 0.36 grams of protein per lb. bodyweight (0.8 grams per kg) per day again in an uneven or even pattern found the pattern of intake didn’t matter. Consuming 2x the RDA, regardless of whether it was consumed in an uneven or even pattern, led to a significantly greater increase in muscle protein synthesis compared to consuming 1x the RDA. The pattern of protein intake didn’t matter, possibly due to age-related decline in muscle response to protein intake,  greater total daily protein intake or some other factor (6).

What Happens to Excess Protein Intake?

There is no long-term storage site for amino acids, the building blocks of protein. After eating a thick juicy steak, creamy bowl of split pea soup or sizzling soy fajitas, your body digests the protein and absorbs the amino acids, using them to build new structures, including muscle. When excess protein is consumed, more than the body needs at that point in time, the rest is used for energy or  converted to body fat. The nitrogen (from amino acids) is combined with other compounds to form urea, a harmless waste product, which is processed by the kidneys and excreted in the urine.

What Influences Protein Requirements?

Though 90 grams in one sitting may be more than necessary for muscle, science has yet to figure out the exact threshold beyond which there is no benefit for muscle. This is a complicated question as there are many factors that influence a person’s daily protein needs as well as how much protein a person may need at each meal. These include but are not limited to: age, training status, total daily calorie intake (if dieting total protein needs are higher), overall amount of protein consumed each day; the type (anti-nutrients?), quality and leucine (or EAA) content of the protein consumed at each meal, other nutrients consumed at meal time, training program, lean body mass, health status and goals.

How Much Protein Do You Need at Each Meal?

Given the research to date, does a per meal does matter?

If you are dieting, yes.

If you don’t get at least 0.55 grams protein per lb. body weight (1.2 grams per kg), yes.

If you eat plenty of protein every day and a decent amount at regular meals throughout the day, it might not matter that much, or at all.

For now, stick to the general guideline of at least 25 grams per meal (the amount of an average female’s palm worth of chicken, turkey, red meat, fish). You may need more, per meal, to maximize muscle growth and repair  if:

  • You are older (relative term since we don’t know exactly what age qualifies as “older). Aim for 1.0 – 1.5 grams of protein per day (7) and regular meals with a good amount of protein per meal. If you have chronic kidney disease, follow the advice of your RD and MD.
  • You eat primarily vegetarian proteins.

Many factors influence a person’s nutrition needs. If you want to maintain or gain muscle mass and strength, concentrate on your total daily protein intake (at least 0.55 grams of protein per lb. of bodyweight; 1.2 grams per kg) followed by how much you consume at each meal. There is no one-size-fits-all ideal protein intake per meal and the body doesn’t just “waste” protein that isn’t used for muscle building. For now, research suggests 25 to 45 grams per meal is a good general guideline. More may be better for muscle. Less may be necessary if you have chronic kidney disease.

Table: Quantity of dietary protein intake, but not pattern of intake, affects net protein balance primarily through differences in protein synthesis in older adults (select data and average leucine intake calculated)

Amount Pattern Meal Protein (grams) Protein as a % of total calories Average leucine intake per meal (calculated)
1x RDA Uneven Breakfast 11.1 8 0.89
Lunch 14.9 8 0.89
Dinner 47.8 12 3.56
Total 73.7 10 4.45
Even Breakfast 22.3 15 1.63
Lunch 21.5 9 1.63
Dinner 22.0 9 0.81
Total 65.8 11 4.07
2x RDA Uneven Breakfast 18.1 15 0.80
Lunch 24.3 12 1.60
Dinner 78.4 22 4.79
Total 120.8 19 7.99
Even Breakfast 38.0 25 2.98
Lunch 36.5 17 2.98
Dinner 37.9 18 2.23
Total 112.4 19 8.2

References

1 Mamerow MM, Mettler JA, English KL, Casperson SL, Arentson-Lantz E, Sheffield-Moore M, Layman DK, Paddon-Jones D. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. J Nutr. 2014 Jun;144(6):876-80.

2 Moore DR, Churchward-Venne TA, Witard O, Breen L, Burd NA, Tipton KD, Phillips SM. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. J Gerontol A Biol Sci Med Sci 2015;70(1):57-62.

3 Loenneke JP, Loprinzi PD, Murphy CH, Phillips SM et al. Per meal dose and frequency of protein consumption is associated with lean mass and muscle performance. Clin Nutr 2016 Apr 7.

4 Symons TB, Sheffield-Moore M, Wolfe RR, Paddon-Jones D. A moderate serving of high-quality protein maximally stimulates skeletal muscle protein synthesis in young and elderly subjects.J Am Diet Assoc 2009;109(9):1582-6.

5 Deutz NE, Wolfe RR. Is there a maximal anabolic response to protein intake with a meal? Clin Nutr 2013;32(2):309-313.

6 Kim IY, Schutzler S, Schrader A, et al. Quantity of dietary protein intake, but not pattern of intake, affects net protein balance primarily through differences in protein synthesis in older adults. Am J Physiol Endocrinol Metab 2015;308(1):E21-8.

7 Paddon-Jones D, Campbell WW, Jacques PF, Kritchevsky SB1, Moore LL, Rodriguez NR, van Loon LJ. Protein and healthy aging. Am J Clin Nutr 2015 Apr 29.

 

 

Effective Strategies for Weight Loss

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Last Friday I spoke at the NSCA’s Personal Trainers meeting in Las, Vegas. They put on one heck of a meeting and I love meeting NSCA members and learning from them as well as the speakers. And one thing I really liked about this meeting was the fact that several speakers challenged commonly held beliefs about nutrition and exercise. Here’s a condensed overview (not all points included) of my talk on Effective Strategies for Weight Loss:

1) Lift Weights or engage in some other type of resistance training, regularly. Muscle tissue doesn’t burn many more calories than fat (despite what people say) – about 4 calories more per day per pound. But, those calories add up over time and more importantly, adults start a gradual slow progression of losing muscle around age 40 (sarcopenia). Less muscle means you can’t exercise as hard which means you won’t burn as many calories while working out (and those activities of daily living like washing your car or lifting groceries will seem tough at some point).

2) Calories Matter. I hate to burst anyone’s bubble who thinks you can eat as much as you want as long as you slash so called “bad calories,” but calories count. If you don’t believe me, check out how nutrition professor Mark Haub lost 27 lbs and significantly improved his blood lipids on a 10-week diet of Twinkies, Doritos, sugary cereals and Hostess cupcakes. Want more evidence published in research journals? Okay, check out the POUNDS LOST trial which found that how much you eat matters more than the proportion of fat, carbohydrate and protein. And, that adherence to a diet determines success (and sticking with extreme diets that cut out food groups sucks so many people don’t last long on them).

3) Calories Matter but Protein is Crucial. Protein preserves muscle during weight loss and the lower your diet is in calories, the more you need protein. How important is protein for preserving muscle? Well, I love the overfeeding study published in JAMA earlier this year in which the study authors overfed participants by 40% more calories than they needed to maintain their weight. The participants were randomized to receive either 5%, 15% or 25% of their calories from protein. Now, 5% may seem low but because of their total daily caloric intake that 5% meant 47 grams per day – that’s 1 gram more than the protein RDA set by our government for women! All groups gained a similar amount of fat and the 15% and 25% group also gained muscle (and therefore more total weight) but, the group consuming 1 gram of protein more than the RDA set for women LOST 0.70 kg lean body mass! Take home points: over consume calories and you’ll gain fat. Make protein a greater proportion of the calories you over consume and you’ll also gain muscle. Follow the RDA and you may lose lean body mass.

4) Change your Environment for Success. Eat off smaller plates and bowls, choose smaller packages, get the food you don’t want to eat out of your house (if it is there, you will eat it at some point). Put healthy food within your line of vision. Avoid constant refills (chip basket at restaurants, bread basket, that never ending tub of beer bottles). And, surround yourself with people who encourage your success vs. those who will get in the way.

5) Keep your stress levels down. For more information on how stress impacts weight, click here.

6) Figure out WHY you are eating. You can have all the nutrition knowledge in the world and weight loss strategies but if you don’t delve into what is making you eat vs. using other coping mechanisms, long term success will elude you.

Now, you are probably wondering “well what about Forks Over Knives, the documentary that covered the supposed evils of animal protein?” I promise I’ll give my uncensored opinion (slashing) of that documentary in my next post in addition to more about protein 🙂

For a hilarious and insightful overview of this conference, check out fitness and nutrition expert Alan Aragon’s post. And, here’s a post from another one of my favorite writers, renowned fitness expert Brad Schoenfeld.