Protein: Grams or % of Calories?

kpsyche wrote: »

Personally I think that without knowing the medical history, weight, age, gender, ethnicity, physical activity level and a whole other bunch of factors about a person, recommending anything other than 0.8g/kg of body weight is not advisable. I know that many fitness coaches recommend way more than that and I often see 0.8/lb cited on MFP (every time I see someone mention 0.8g/lb I wonder if they really mean 0.8g/kg).

Based on 0.8g/kg if the OP's weight is somewhere in the neighbourhood of 65kg (I have no idea if they are or not) then 50g of protein a day is probably adequate and consistent with the dietary guidelines of Europe, the USA, WHO and probably nearly every other country.

From WHO Protein and amino acid requirements in human nutrition
"The value accepted for the safe level of intake is 0.83 g/kg per day"
"It is unlikely that intakes of twice the safe level are associated with any risk.
However, caution is advised to those contemplating the very high intakes of
3–4 times the safe intake, since such intakes approach the tolerable upper
limit and cannot be assumed to be risk-free."

0.83g/kg/day is 0.38g/lb/day. An intake of 0.82g/lb/day is 1.8g/kg/day (only about twice the amount discussed in the WHO report, and many others, so probably safe). I start getting annoyed though when I see people on MFP consistently recommending to others that they eat more protein than leading world health organisations recommend; I don't know if it's because of a confusion between metric/imperial units and this has led to the perpetuation of error, or if there is some other reason behind the sometimes excessive recommendations for daily protein consumption.

deannalfisher wrote: »

kpsyche wrote: »

Personally I think that without knowing the medical history, weight, age, gender, ethnicity, physical activity level and a whole other bunch of factors about a person, recommending anything other than 0.8g/kg of body weight is not advisable. I know that many fitness coaches recommend way more than that and I often see 0.8/lb cited on MFP (every time I see someone mention 0.8g/lb I wonder if they really mean 0.8g/kg).

Based on 0.8g/kg if the OP's weight is somewhere in the neighbourhood of 65kg (I have no idea if they are or not) then 50g of protein a day is probably adequate and consistent with the dietary guidelines of Europe, the USA, WHO and probably nearly every other country.

From WHO Protein and amino acid requirements in human nutrition
"The value accepted for the safe level of intake is 0.83 g/kg per day"
"It is unlikely that intakes of twice the safe level are associated with any risk.
However, caution is advised to those contemplating the very high intakes of
3–4 times the safe intake, since such intakes approach the tolerable upper
limit and cannot be assumed to be risk-free."

0.83g/kg/day is 0.38g/lb/day. An intake of 0.82g/lb/day is 1.8g/kg/day (only about twice the amount discussed in the WHO report, and many others, so probably safe). I start getting annoyed though when I see people on MFP consistently recommending to others that they eat more protein than leading world health organisations recommend; I don't know if it's because of a confusion between metric/imperial units and this has led to the perpetuation of error, or if there is some other reason behind the sometimes excessive recommendations for daily protein consumption.

WHO recommendations (typically) aren't for people physically active but rather minimum based on sedentary individuals

kpsyche wrote: »

deannalfisher wrote: »

kpsyche wrote: »

Personally I think that without knowing the medical history, weight, age, gender, ethnicity, physical activity level and a whole other bunch of factors about a person, recommending anything other than 0.8g/kg of body weight is not advisable. I know that many fitness coaches recommend way more than that and I often see 0.8/lb cited on MFP (every time I see someone mention 0.8g/lb I wonder if they really mean 0.8g/kg).

Based on 0.8g/kg if the OP's weight is somewhere in the neighbourhood of 65kg (I have no idea if they are or not) then 50g of protein a day is probably adequate and consistent with the dietary guidelines of Europe, the USA, WHO and probably nearly every other country.

From WHO Protein and amino acid requirements in human nutrition
"The value accepted for the safe level of intake is 0.83 g/kg per day"
"It is unlikely that intakes of twice the safe level are associated with any risk.
However, caution is advised to those contemplating the very high intakes of
3–4 times the safe intake, since such intakes approach the tolerable upper
limit and cannot be assumed to be risk-free."

0.83g/kg/day is 0.38g/lb/day. An intake of 0.82g/lb/day is 1.8g/kg/day (only about twice the amount discussed in the WHO report, and many others, so probably safe). I start getting annoyed though when I see people on MFP consistently recommending to others that they eat more protein than leading world health organisations recommend; I don't know if it's because of a confusion between metric/imperial units and this has led to the perpetuation of error, or if there is some other reason behind the sometimes excessive recommendations for daily protein consumption.

WHO recommendations (typically) aren't for people physically active but rather minimum based on sedentary individuals

Rubbish. They are for active, healthy people as are the dietary guidelines for the US, Europe, Oceania and every other guideline in the world that I've seen.

kpsyche wrote: »

Personally I think that without knowing the medical history, weight, age, gender, ethnicity, physical activity level and a whole other bunch of factors about a person, recommending anything other than 0.8g/kg of body weight is not advisable. I know that many fitness coaches recommend way more than that and I often see 0.8/lb cited on MFP (every time I see someone mention 0.8g/lb I wonder if they really mean 0.8g/kg).

Based on 0.8g/kg if the OP's weight is somewhere in the neighbourhood of 65kg (I have no idea if they are or not) then 50g of protein a day is probably adequate and consistent with the dietary guidelines of Europe, the USA, WHO and probably nearly every other country.

From WHO Protein and amino acid requirements in human nutrition
"The value accepted for the safe level of intake is 0.83 g/kg per day"
"It is unlikely that intakes of twice the safe level are associated with any risk.
However, caution is advised to those contemplating the very high intakes of
3–4 times the safe intake, since such intakes approach the tolerable upper
limit and cannot be assumed to be risk-free."

0.83g/kg/day is 0.38g/lb/day. An intake of 0.82g/lb/day is 1.8g/kg/day (only about twice the amount discussed in the WHO report, and many others, so probably safe). I start getting annoyed though when I see people on MFP consistently recommending to others that they eat more protein than leading world health organisations recommend; I don't know if it's because of a confusion between metric/imperial units and this has led to the perpetuation of error, or if there is some other reason behind the sometimes excessive recommendations for daily protein consumption.

The protein requirements of adult men and women of various body weights are shown in Table 46. For adults, the protein requirement per kg body weight is considered to be the same for both sexes, at all ages, and for all body weights within the acceptable range. The value accepted for the safe level of intake is 0.83 g/kg per day, for proteins with a protein digestibility-corrected amino acid score value of 1.0. No safe upper limit has been identified, and it is unlikely that intakes of twice the safe level are associated with any risk. However, caution is advised to those contemplating the very high intakes of 3–4 times the safe intake, since such intakes approach the tolerable upper limit and cannot be assumed to be risk-free.

13.6 Is there a maximum limit of dietary protein intake? As indicated above, in developed countries most people consume substantially more protein than the safe level, especially through consumption of meat-based diets at energy intakes required to meet the demands of high levels of physical activity, or with supplementary protein intakes often consumed by young men attempting to increase their musculature. Typical intakes are
up to 3.0 g/kg from food (72) with an extra 1 g/kg from supplements. This is equivalent to 320 g/day for an 80-kg male, and at energy intakes which match an expenditure of twice the basal metabolic rate (i.e. 3800 kcal/day). This implies an overall protein:energy ratio of the diet of 34% (see 72). Such intakes are similar to those involved in studies of the impact of dietary protein intake on nitrogen balance, where protein intakes were increased to
200–300 g/day for 2 months (73). Such practices are almost certainly ineffective in terms of gain of muscle mass, even though substantial nitrogen retention is often reported (73, 74). Where measurements of muscle mass or
protein concentration are made no changes are identified (75), suggesting the apparent gain in body nitrogen to be an artefact of the nitrogen balance method at these very high intakes, possibly with an unmeasured source of
loss of nitrogen (71, 76).

While there have been no systematic investigations of the safety of such high intakes (at least to the current available knowledge), it must be assumed, given that such dietary habits are widespread, that any untoward effects are subtle, long-term and unreported. The most widely quoted potential problems relate to renal function and damage, but as discussed above the evidence for such claims in otherwise healthy individuals does not stand up to scrutiny. Similarly, any adverse impact on bone mineral balance would appear to be more than adequately balanced by the positive influence of weight-bearing exercise in strength training, judging by most reports of high bone mineral content in power athletes.

As for a safe upper limit for adults, we can be reasonably confident that an intake of twice the recommended intake, previously identified as a safe upper limit, is likely to be safe given that it equates to intakes of physically active individuals consuming average mixed diets who would otherwise be identified as having healthy lifestyles. It is also clear that there is an upper limit to the protein content of food, which is identifiable by the individual in terms of the nausea and diarrhoea of “rabbit starvation”, although exactly what that limit is has not been identified. Many individuals consume intakes of 3–4 times the recommended intake, possibly for relatively long periods of time, without (presumably) exhibiting such symptoms; while no specific evidence for harm, can be identified neither the fact nor such intakes are risk-free can be insured. Given the lack of evidence of benefit in terms of athletic performance or physique, it might be prudent to avoid such intakes (90). Protein is the most satiating macronutrient, and protein supplements may lead to suboptimal intakes of those starchy foods essential for both performance and long-term health, and insufficient dietary alkali derived from fruit and vegetables to buffer the protein-derived acid load, with adverse effects on bone. High-protein diets can both increase exercise-induced amino acid oxidation, especially in untrained individuals and those with an inadequate energy intake, and increase risk of negative nitrogen balance and loss of lean body mass between training periods when high intakes are reduced (91). Clearly, with minimum protein intakes to maintain appropriate body composition and function that are probably much lower than intakes of individuals with healthy lifestyles consuming usual mixed diets, there is a need to improve our understanding of the relationship between protein intakes and overall health. This is a particularly important area for future research.