60+ % of calories from protein is preposterous.
Sounds high to me too based on the RDIs. You'll go into ketosis because your body needs carbs as it's basic, NECESSARY requirements to fuel the cells in your body.
To be best of my knowledge, this statement is untrue. All cells in the body are quite quite happy metabolising fatty acids with the exception of the brain (FAs can't pass through the blood-brain barrier). Ketone bodies are produced in the liver and transported through the blood into the brain where they are incorporated into acetyl-CoA and then fed into the citric acid cycle for normal metabolism. Typically, a short period of adaptation (days, from memory) is required before the brain will happily switch over to ketone metabolism full time. You don't get enough carbs and you'll just turn that protein into the carb fuel that your body needs... why waste all that energy?
Correct. It's not the waste of energy that's of concern (unless you live in the 3rd world), it's the stress put on the kidneys to clear the increased levels of uric acid. A good reason (along with many others) to keep well hydrated. Also, that excess protein will not maintain your muscle mass. Protein will not create or maintain muscle. Only weight bearing exercise will.
Actually, this statement has been found to be untrue. REF: Med Sci Sports Exerc. 2010 Feb;42(2):326-37.
Increased protein intake reduces lean body mass loss during weight loss in athletes. Infants only eat (from mother's milk) 6-8% of calories from protein.
This statement is true.I'm pretty sure they need WAY more protein than any athlete on this planet.
Per KG of bodyweight, yes. Overall, nope. More information here for people looking: http://www.fao.org/docrep/003/aa040e/AA040E07.htm
. My guy feeling, if you excuse the pun, is that infants don't provide a meaningful model for comparison. Macronutrient profiles will (largely) suit what the child needs at that particular time. For example, let's assume that the average 6 month old consumes 900ml of breast milk /24 hour period (http://www.kellymom.com/bf/pumping/milkcalc.html
with references provided) and breastmilk contains on average ~70kCal/100ml (http://www.unu.edu/unupress/food/8F174e/8F174E04.htm
) and the average 6 month old boy weighed in at 8kg, total ave calorie consumption/24hrs = 630kCal or per kg of body weight, 79kCal/kg of body weight. Let's say that your average joe weighs in at a feathery 80kg, if he ate the equivalent of a baby at 6 months, he'd be consuming 6320kCal per day. Hmmm.
What's my point? The macronutrient needs of an average growing baby is different to that of a fully grown adult who is not growing but has more lean mass to maintain. The 6-8% figure does not give an indication of total calories consumed. Protein needs decrease with age when measured in g/Kg body mass, but body mass increases with age and thus protein consumption will go up (to a point). However, energy requirements are likely to decrease once adulthood is passed and growth has stopped (but muscle mass is still being maintained) thus calories required from CHOs/lipids needed to maintain weight will decrease (so g/kg of protein remains stable whilst the others drop but as a % of total calories consumed, % protein increases.) Obviously, these are generalisations and lifestyle/body composition/genetics will influence actual dietry needs. Also, I read an article or an interview by an olympic dietician and they say no matter what your sport, exercise/activity level, etc. you shouldn't change your caloronutrient ratio.
You shouldn't change from what? There is plenty of peer reviewed evidence that indicates that 1. there have been changes/evolution in macronutient content of our diets over generations and 2. these changes, in part, are the cause of the obesity/metabolic syndrome epidemic that plagues our western society today (and exercise/activity, lifestye (stress levels) and genetics make up the other components) Nutr Rev. 2010 Apr;68(4):214-31.
I can't remember which specific paper I saw it in but it showed that over the past 50 years, in US diets, protein content had remained somewhat stable, fat levels had actually come down but CHOs, in particular, high GI CHOs, had seen a large increase in consumption. The question is, are we adapted to be consuming all of these high GI CHOs? Looking into our past (pre-agriculture) and what we ate might provide us with some clues about what we're best adapted to be eating. eating.http://en.wikipedia.org/wiki/Glycemic_index
- references 16/17 are quite interesting.
Whilst calories in vs calories out is largely true (to a point, think caffeine consumption and increases in BRM, for example), consumption of lower GI foods - particularly protein - leads the test subjects feeling fuller for longer and thus reduces the incidence of binge eating (and therefore excessive calorie consumption). The only thing that changes is calories. They also spent a while doggin' on American's for eating too much protein (the average American eats somewhere in the range of 18-20% of calories from protein).Eat even 30+ % calories from protein for two months and tell me how you feel after.
If you added that extra 10% at the expense of high GI carbs from your diet, science demonstrates that your body composition/blood work would most likely improve. I pity the fool who eat low-carb.
100% agreed! The world would be a far less tollerable place without my midnight freezer icecream raids.