What nutrition societies recommend
The German Nutrition Society (DGE) recommends 0.8 g of protein per kilogram of body weight per day for adults up to 65. From 65 it gives 1.0 g as an estimate. These values cover the needs of almost all healthy people who move little. They are a floor for adequate supply, not an optimum for training or weight loss.
For people who train regularly, the International Society of Sports Nutrition (ISSN) names 1.4 to 2.0 g per kilogram per day (Jäger et al. 2017). A meta-analysis of 49 studies found that extra protein improves muscle gain from resistance training up to about 1.6 g per kilogram. Above that, little more was gained on average, though some people benefited up to about 2.2 g (Morton et al. 2018).
Why HabitHelm suggests 1.6 or 1.8 g per kilogram
For losing fat and building muscle, HabitHelm suggests 1.8 g per kilogram, for gaining weight and cycling 1.6 g. In a calorie deficit, more protein helps keep muscle. Studies in lean, trained people in a deficit even name 2.3 to 3.1 g per kilogram of fat-free mass (Helms et al. 2014). You can change the value in the coach under goals.
At a high body weight: Above a BMI of 30, HabitHelm does not use your current weight but your target weight. Without a target weight, it uses the weight that equals a BMI of 25. Otherwise the target would quickly exceed 200 g of protein a day. That is hard to eat and brings no benefit, because fat tissue needs very little protein.
If you have kidney disease, agree on your protein intake with your doctor. For healthy kidneys there is no evidence that these amounts cause harm.
Spreading protein over the day
After a meal, the body builds more muscle protein for a few hours. The ISSN therefore recommends 20 to 40 g of protein per meal, every three to four hours. The amino acid leucine is the main trigger for this signal. The ISSN names 0.7 to 3 g of leucine per meal. That is why HabitHelm shows leucine per meal in protein quality and leucine per serving on product pages.
It is not quite that simple, though. A study from Maastricht found a larger and longer building response after training with 100 g of protein than with 25 g (Trommelen et al. 2023). The total for the day matters more than the exact distribution. HabitHelm therefore shows leucine as an orientation and does not rate single meals.
Protein quality: not every gram is equal
Protein is made of 20 amino acids. Your body cannot make nine of them, so they have to come with food. WHO, FAO and UNU set in 2007 how much of each you need per kilogram of body weight per day. HabitHelm compares your day with these values when you switch on protein quality.
The FAO also rates protein sources with the DIAAS, which includes digestibility. From 75 a protein counts as high quality, from 100 as excellent. Milk and whey protein are usually above 100, soy around 90, pea and cereal protein often lower (Herreman et al. 2020). Plant sources complement each other well, for example legumes with grains. The DIAAS is not on the label, so HabitHelm does not show it per product.
Sources
- German Nutrition Society (2017): New reference values for protein. dge.de
- Jäger R, Kerksick CM, Campbell BI et al. (2017): International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition 14:20. doi.org/10.1186/s12970-017-0177-8
- Morton RW, Murphy KT, McKellar SR et al. (2018): A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength. British Journal of Sports Medicine 52(6):376–384. pubmed.ncbi.nlm.nih.gov/28698222
- Helms ER, Aragon AA, Fitschen PJ (2014): Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition 11:20. pmc.ncbi.nlm.nih.gov/articles/PMC4033492
- Trommelen J, van Lieshout GAA, Nyakayiru J et al. (2023): The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans. Cell Reports Medicine 4(12):101324. doi.org/10.1016/j.xcrm.2023.101324
- WHO, FAO, UNU (2007): Protein and amino acid requirements in human nutrition. WHO Technical Report Series 935.
- Herreman L, Nommensen P, Pennings B, Laus MC (2020): Comprehensive overview of the quality of plant- and animal-sourced proteins based on the digestible indispensable amino acid score. Food Science & Nutrition 8(10):5379–5391. pmc.ncbi.nlm.nih.gov/articles/PMC7590266