• 'The evidence indicates that there is little effect of total protein intake on the incidence of cancer, but that specific foods, such as red or processed meat, might increase the risk relative to vegetable protein sources'.

• 'Healthier lean protein sources, such as legumes, fish and poultry should be prioritised over red and processed meats, which should be limited. This is especially the case for colorectal cancer, where the evidence for processed meats and an increased colorectal cancer risk is particularly strong'.

Health Council of the Netherlands 2021 (pdf)

• ‘the Committee concluded that increased protein intake has a possible beneficial effect on lean body mass in older adults, which does not involve any change in body weight’.
• ‘the Committee concluded that increased protein intake has likely no effect on bone health in older adults.’ 

SACN 2026 (pdf)

• ‘There was very low certainty evidence from prospective cohort studies that higher maternal protein intake may be associated with excess GWG (gestational weight gain) in women with a range of BMIs’.

SACN 2024

• Moderate evidence suggests that ‘higher total protein intake in children aged 1 to 5 years is associated with higher body mass index (BMI) in childhood’. 

SACN 2018 (pdf)

• ‘Evidence from RCTs comparing higher versus lower infant formula protein contents supports observational evidence linking higher intakes of animal protein in infancy to rapid weight gain and later risk of obesity’

• 'Taken together, it does appear that dietary protein as part of a well-balanced diet is most likely to be beneficial for bone, possibly at dietary levels in excess of the recommended intake'.
• 'The fact that our current models of protein and energy requirements identify sedentary elderly people as most likely to be at risk from protein deficiency (…), together with the evidence of a beneficial effect of dietary protein on bone in elderly people, suggests that attention should be given to the provision of protein-dense foods to this particular population group'.

• 'A favourable effect on bones seems to be likely: studies reveal a positive association between the level of protein intake and bone mineral density, without, however, indicating any reduction in the risk of fractures'.

Kidney stones

• 'Although some studies suggest that high animal protein intake might increase the risk of kidney stones, particularly in those subjects who are classified as idiopathic calcium stone formers, as yet no clear conclusions can be drawn since dietary effects are apparent only in studies with very large differences in protein intakes (i.e. >185 g/day compared with 80 g/day)'.
• 'it is not yet clear whether there is a difference between proteins of animal versus plant origin'.
• 'in order to minimize the risk of kidney stones in patients who are at risk, the diet should ideally provide at least the safe level (0.83 g/kg per day), but not excessive amounts (i.e. less than 1.4 g/kg per day), preferably from vegetable sources'.

• 'repetition of strength exercises leads to an increase in protein requirements, but, generally speaking, the protein requirements necessary for nitrogen balance equilibrium are covered by a balanced diet. The dietary habits of strength athletes mean that their protein intakes far exceed the quantities that can be recommended. It is training that explains the increase in muscle mass, and the protein intakes are justified by the necessary availability of amino acids to ensure increased synthesis of structural and functional proteins'.

Muscle mass  in elderly

• ‘the Committee concluded that increased protein intake alone (not in the context of physical exercise) has likely no effect on muscle strength in older adults. In contrast, the Committee concluded that increased protein intake with concomitant physical exercise (predominantly resistance exercise training) does have a possible beneficial effect on muscle strength in older adults, compared to physical exercise alone.’

Physical function

• ‘the Committee concluded that increased protein intake has likely no effect on physical function in older adults'.