How much protein should I eat?

Protein can aid recovery, better body shape and support muscle mass but how much do you eat?

If you’re worried about strength, athletic performance and body shape you have probably thought about your protein intake at some point. There’s a lot of info out there and a lot of opinion – most of it revolving around the issue of muscle mass. So how much protein do you need?

When you ask this question you’re really asking

• How much should you eat? And,
• How much protein can you eat in a sitting?

Reasons to eat more protein: It’s more than just about your muscles you know!

“Question: I’ve read that you don’t need any more than 20g of quality protein in a sitting to get maximum stimulation of muscle protein synthesis, so I shouldn’t bother with any more, no?”

When you eat quality protein the concentrations of amino acids in the blood rise. This rise, if big enough can stimulate the body to lay down more protein in the form of muscle tissue. We like this. A lot. However, recently studies have shown that protein synthesis plateaus out at about 20-25g of protein in a sitting. With many nutrition protocols and professionals advising you to eat maybe double or more per sitting, why would you consider eating any more?

1) It gives you calories whilst displacing others

Think about someone eating 5 meals a day at 25g of protein:

25 – number of grams of protein per sitting

5 meals a day

4  – number of kcals per gram of protein

25 x 5 x 4 (kcals/g) = 500 kcals (per day from protein)

If you train you may well be eating well over the usual 2000-2500 kcal recommendations. So where are the rest of you calories coming from? Fats and carbohydrates.

500 kcals from daily protein intake

3800 total daily calories for hard training

3800 – 500 = 3300 kcal (from fats and carbs)

this equals 536g of carbohydrates and 128g of fats

(using a 65/35 ratio of carbohydrate to fat)

That’s a lot of carbohydrate and fat and for most people will be an issue over time both body composition and health wise.  Protein also has a few very useful properties that fat and carbs don’t. To wheel out the old quote again

A calorie is not a calorie!

2) Increased satiety from meals

Your body has mechanisms to regulate your food intake and it’s well demonstrated that an increase in protein (at the expense of other macronutrients) has a real effect upon total energy intake, for example in the American Journal of Clinical Nutrition we find the paper by Weigle et al, where an increase in protein intake (from15% to 30% of energy intake) with a simultaneous reduction in fat (from 35% to 20%, carb intake unchanged), produced a sustained decrease in calorie intake and significant weight loss .

3) Insulin versus glucagon

We all know the issues associated with chronically elevated insulin levels from large amounts of carbohydrates (see calcs above!), well, glucagon is the antagonist to this. It helps lower insulin levels and does a other metabolic tricks that support health and good body comp.

4) Lower GI/II of your meals

Depending upon the protein source, it can slow down the transit of the other contents of the meal through the gut. Here we’re talking about the carbohydrate. It effectively lowers the Glycemic Index of your meal – again, good for all the same reasons as switching from high to low GI carbs are.

5) The thermic effect of protein

Your resting metabolic rate, the calories you burn at rest, increases in the hours after you eat. This is because you burn energy digesting and assimilating the macronutrients you eat; but not all macros are the same in this respect. The following is the % of the cals you eat that are expended

Protein = 20-30%

Carbohydrate = 5-10%

Fat = 0-5%

In effect it is a small part of the picture, maybe roughly 4-12%, but it helps, and of course with higher protein diets this effect would be towards the high end.

6) Accessory nutrient and specific amino acids

Obviously we’re talking about protein but you get (hopefully most of) your protein from whole foods. Examples of these are leans meats and oily fish – in these we find micronutrients: important vitamins and minerals and fats/lipids: omega 3 fatty acids and others like CLA.

We’re also understanding more and more about the almost pharmacological effect of some amino acids like leucine and phenylalanine.

7) Nitrogen balance

If you have a decent amount of protein entering the body then the metabolic machinery is more able to utilise the protein and aid recovery. Indeed this can lead to a ‘positive nitrogen balance’ where more nitrogen (the marker from protein) is going in than going out – this gives strong clues to an net anabolic environment in the body – i.e. muscle and recovery.

7) Protein turnover

Connected with the nitrogen balance, the chemical building blocks of your body are turned over, being processed out and replaced from many of the structures of your cells. If you eat more protein you stimulate the breakdown of the protein in your muscle, but you also stimulate synthesis as well – this means more new muscle tissue and great opportunity for growth.

9) other benefits….

I’m not glossing over these I just thought I may be boring you by now… they include the stimulation of IGF-1 (the anabolic hormone) production, supporting of immune system competence, reduction in fatty acid synthesis. There’s more which I am sure I have forgotten at this point

…so why does this all matter?

These factors all add up, increasing the protein in diets based on already healthy choices has been shown to

• Aid lean body composition
• Increase fat and ‘weight’ loss
• Increase HDL levels in the blood, the ‘good’ cholesterol
• Decrease triglycerides and LDL levels – two strong correlates (the 1^st especially) to cardiovascular health.

So a leaner, healthier body. Good. But how much can you eat per sitting?

Maximum protein absorption per sitting

Anyone who has spent more than a little time frequenting interweb chat rooms and forums dedicated to strength sports and bodybuilding has seen the age old question:

“How much protein can I absorb in one sitting? The [supplement tub/guy at GNC/PT] says

it’s about 30g, is this true?”

As Christian Thibaudeau puts it, it’s more complex than the 30g watermark. The two main factors involved are what you’re eating and how your gut is working.

1. What you’re eating

The type of protein you are using

The slower digesting your protein is then the more chance your body has to ‘capture’ those amino acids and then do something useful with them. Meat and casein proteins are a good example of these.

The meal you eat

Both fibre and fat will slow digestive processes and in the same way give your body a little more time to work on the protein you’ve eaten.

2. Your ability to deal with it

Everyone has different levels of gut health. The gut is an incredibly complex bit of kit. There’s dozens of hormones and billions of neurons associated with it’s function not to mention all the many strains of bacteria, delicate epithelium cells etc etc. The healthier the gut, the better it can work.

So how much protein in one sitting? How long is a piece of string?

The bottom line

Adding together the factors of why protein is useful and also the capacity to digest and absorb, leads to a wide range of recommendations, especially when talking about people with different body composition, body shape histories and goals…

• For men: 35-65g per sitting
• For women: 25-40g per sitting
• Eating this with whole foods in each of the 4-6 meals in the day.

Just make sure you chose as good a source of protein as possible; lean, grass fed, organic…. these are all words you should be looking out for…

FOOTNOTE: My girlfriend just pointed out ‘but what about veggies?’. Well the same rules apply as always: you have to push those concentrated sources of protein. See the vegan shopping list and the flexitarian experiment posts for more ideas on how to do this.