Protein is a building block for all our cells, so becomes vital in building muscle - and the health benefits of building muscle mass are plentiful. It has an important role to play in tissue repair, forms the foundation of developing vital hormones and can balance blood sugar levels. But do you know how much protein you need and why?
Protein intake
As a general rule, adults need 0.8-1.2g protein per kilo bodyweight on a daily basis as a minimum. There are always exceptions to a rule, one of which is when you are looking to build lean muscle (1.2-2g/kg bodyweight), when you are pregnant or breastfeeding (add another 6g/kg bodyweight) and when trying to lose weight (1.6-2.2 g/kg bodyweight). If you are increasing your strength training and looking for more muscle tone and definition, you also need to increase your protein intake. This will help support the energy demands required for heavier lifting.
Amino acids
Proteins are made from 20 different amino acids, 9 of which we have to get from food. Animal protein offer a complete amino acid profile (i.e. all 9 essential amino acids), whilst plant sources offer some amino acids, hence plenty of variety is important for vegans/vegetarians. Amino acids, particularly BCAA's, plays an important role in the development and signalling system of female hormones, ensuring availability of adequate amounts of oestrogen, progesterone, human growth hormone and also prolactin for breastfeeding mothers. However, you can get too much of a good thing. A high protein diet, particularly if high animal protein, can be void of sufficient fibre, leading to potential oestrogen excess. Whilst increased protein intake is useful, you still need to have a balanced diet to also get sufficient carbohydrates and fats. If you increase protein intake, make sure you incorporate protein from animal sources (lean meat and dairy) as well as vegetable protein (legumes, beans, nuts and seeds) and ensure all is minimally processed.
Protein and female hormones
Females have different protein requirements depending on age, where they are in their menstrual cycle and requirements change with pregnancy and menopause. Too little protein can cause irregular periods and low energy availability, and limited animal protein combined with heavy periods can lead to an iron deficiency. Protein intake alone doesn't improve PMS, but can help limit cravings caused by hormone fluctuations. If PMS and cramping is an issue, it's more important to consider a more varied diet with plenty of green leafy vegetables, calcium and magnesium.
Research support that peri/post-menopausal women benefit from higher protein intake than the standard RDA (recommended daily intake), in the same region as those looking to build lean muscle. Such protein intake is proven to limit age-related sarcopenia, i.e. loss in muscle mass and is also beneficial for weight loss. A higher protein intake helps with satiety, hence less chance of snacking or overeating. The impact of increased protein intake is more beneficial for women compared to men of the same age, presumably due to the naturally occurring shift towards a higher body fat % in women during peri/postmenopausal years.
Sources of protein
As with everything, you need to take a balanced approach to your protein intake, using a variety of sources. As an easy reference point, get as many grams of protein as you weigh (and then some) every day: If you weight 70kg, aim for minimum 70g-100g of protein/day. The below infographic gives you plenty of alternatives. Try to focus on plant-based proteins and certainly minimally processed protein options.
(source: @thefitnesschef)
Further reading / references:
Do mothers need more calories while breastfeeding? https://www.cdc.gov/breastfeeding/breastfeeding-special-circumstances/diet-and-micronutrients/maternal-diet.html
Nutrition During Pregnancy: Part I Weight Gain: Part II Nutrient Supplements.
RESEARCH REVIEW: ADEQUATE DIETARY PROTEIN HAS ASSOCIATED BENEFITS FOR POSTMENOPAUSAL WOMEN (60-90 YEARS) https://blog.nasm.org/protein-for-post-menopausal-women
Protein Intake and Functional Integrity in Aging
Exercise, diet and periods