How much protein should I be eating?

Question

I am 59 yrs old, 6'5" and I currently weigh 245lbs, up from my lowest of 230lbs, after having lost 110lbs last year. I have a desk job during the day and I work out with weights 3 times a week for about 45 mins per session then some cardio for 25 to 30 mins after.

I am eating protein 40%, fat 35%, carbs 25% as instructed by my weight-loss coach and RD. My BMR is 2700-3600 cals/day.

I am gaining weight but I don't think the weight I have gained is muscle. How much protein should I be eating?

I know for serious bodybuilders and weightlifters its at least 1-to 1 ratio or more, but what should it be for me?.

Answer 1

My answer will focus on a general analysis of protein intake among all types of people who do all types of exercise and conclude with recommendations for you, specifically, based on the information you have given. Hover over the links to view the full citation, follow them to find the source.

I use a lot of Xg protein per lb/kg of bodyweight in this answer, If you are obese, using a protein intake relative to body weight is a bad idea. You should either calculate your lean mass (overall weight after subtracting fat mass, which can be calculated by body fat percentage) or use your goal/target weight for calculations.

The crux of this problem is "how much protein will be absorbed by my body and how much will be ejected as waste?" It is commonly known that if you eat too much you will absorb the calories and 'eject' the un-absorbed protein.

As quite rightly pointed out in the comments, One gram of protein per pound of body weight (1 g/lb) or 2.2 grams per kilogram (2.2 g/kg) is the traditional recommendation for protein intake. However, this can be considered the upper bound of target intake, with the suggested range spanning 0.45-1g/lb.

Protein: Athleticism and Body Composition

Two Studies in Phillips SM (2004) Cambell WW, et al (1991) indicated that 12-15% of calories from protein is sufficient for active individuals (60-75g of protein for an individual eating a 2000 calorie diet). However, more recent studies Lemon PW, Proctor DN (2000) and Lemon PW (2004) argue for higher intake - the 2000 study reports that greater than 1.6-1.8 g/kg of bodyweight (0.7-0.8 g/lb of bodyweight) may be necessary, while the 2004 study indicates that up to 3.0 g/kg of bodyweight (1.4 g/lb of bodyweight) isn't harmful, and may have additional minor benefits.

According to the International Society of Sports Nutrition, protein intakes of 1.4-2.0 g/kg of bodyweight (0.6-0.9g/lb of bodyweight) for physically active individuals is not only safe, but may improve the training adaptations to exercise training. The American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine also support high protein intake for active individuals in the range of 1.2-1.7 g/kg of bodyweight (0.5-0.8 g/lb of bodyweight).

The reasons for the above recommendations are outlined in Wilson J, Wilson GJ (2006) and Campbell B, et al (2007) and focus on the increased leucine oxidation (a marker for amino acids being used for fuel, by being turned into glucose) that requires a higher intake of amino acids to negate and preserve nitrogen balance.

Additionally, Jeevanandam M, et al (1986) explains that increasing protein intake above the US RDA 'daily allowance' of 46-56g for adults (female/male) will increase protein synthesis and, at levels higher than double this total, decrease protein breakdown. Increased muscular hypertrophy is seen as beneficial to sports performance.

Protein: During Weight Loss

A study of obese and pre-obese women by Leidy HJ, et al (2007) and a study of atheletes by Mettler S, Mitchell N, Tipton KD (2010) both showed that high protein diets have been found to preserve lean body mass when dieting. In addition to these findings, Layman DK, et al (2005) concluded that a high-protein diet improves overall body composition.

A study of healthy men by Pikosky MA, et al (2008) found that a doubling of protein intake from 0.9g/kg (near the daily recommended intake for the general population) to 1.8g/kg is able to preserve lean muscle mass during short-term and relatively drastic drops in calories.

Protein: What is too much?

A meta-analyses of 35(!) studies by examine.com concludes the following:

Don't worry about it if you have healthy kidneys and control your protein intake if you have damaged kidneys. It may be prudent to gradually increase protein intake to higher levels rather than jumping in both feet at a time, but there isn't much on this topic.

It is generally recommended to consume more water during periods when protein intake is being increased. Whether or not this has biological basis is not known, but it may be prudent to do

Protein: Your specific question

To summarise, you are eating at a 45/35/25 split which is the standard recommendation for someone who is weightlifting and looking to gain muscle. It provides you with the protein you need to develop muscle in recovery, and the fats and carbohydrates you need to function and have energy.

You estimate your BMR at 2700-3600 per day. This strikes me as a lot. Plugging your height, weight, age and gender into the iimym BMR calculator I get a BMR of 2064. With an average difference between my estimate and yours of 1000 calories, I recommend you have another look at how you calculated your BMR and perhaps re-do it across lots of calculators to get a sensible average.

Note: If I plug in your exercise data I get a TDEE of 2500 calories per day.

We shouldn't be the rock and eat 400g protein per day. Looking at the information I have presented above and the studies referenced it's fairly clear that your macronutrient breakdown (ratio of carb/fat/protein) is fine. What is made clear is you should perhaps look at how many calories you are consuming, below is one sites (iimym.com) recommendation:

Answer 2

Every clinical trial involving weight loss shows the same results, where people lose weight for up to 6 months and then start to regain from that point. It is commonly believed that weight is regained because people start increasing calories. In fact, as the A-Z trial shows, and as you already know from experience, when people get on the scale and find that weight is coming back on, they redouble their efforts, further restricting calories and working out harder. Unfortunately, and counter intuitively, further caloric restriction does not help.

The reason is that as weight is lost, the body responds with hormonal regulation. Ghrelin and Leptin, which regulate appetite and energy balance, are affected. Energy levels change; BMR changes in ways we don't quite understand. Anyone who has participated in marathon training and gained weight, which many have, knows that something more is going on than calories in and calories out.

So, if you have found that counting calories is not working for you anymore, perhaps it is time to look at regulating hormones. Many people find they can regulate Ghrelin and Leptin, and therefore hunger, with a very low carbohydrate and moderate protein diet. More importantly, Insulin resistance must be countered. Insulin resistance is caused by two much insulin due to blood sugar regulation (eating too much carbohydrate), and insulin too often (eating too often). To fix this problem, eat fewer carbohydrates, and eat less often. I suggest thoroughly reading Intensive Dietary Management. Unfortunately, there are not yet clinical trials to directly support the approach. But, there are numerous trials that debunk the approach of further lowering calories.