“High in Protein”. That’s what you hear when health and fitness influencers are showing you how to make low calories meals that taste good and will help you lose weight. Why do they feel they have to advertise the Protein though?
My thinking is that each macro-nutrient is of equal importance to the body. They each have their essential functions.
Carbohydrate provides our body with energy. This energy keeps us alive by keeping our organs functioning, especially our brain.
Fat can also be used as energy. A layer of subcutaneous fat (under the skin) called adipose tissue acts as insulation keeping us warm. It also protects delicate organs. Provides fat soluble vitamins A.D.E & K. Plays a structural role in the cell membrane (our bodies are made of cells, so this is important)
Then there’s Protein. It has a lot of important functions. Protein plays a role in the growth and repair of muscles. Hormone’s function, enzyme function and immune function also depends on Protein. Protein also controls our body’s pH by acting as a buffer (so we don’t become too acidic).
So as you can see, all three nutrients are pretty important. Over the years different nutrients have been demonized for different reasons. First it was fat, now it seems to be Carbs…but Protein seems to be the golden child that can do no wrong!
First off, I want to clarify that 1g of carbohydrate offers the same number of calories as 1g of Protein, 4Kcals. Also, just like if you overconsume carbohydrates or fats, meaning you eat more than you burn off, if you consume more Protein than you burn off it will be stored as fat.
How Much Protein Do You Need?
It’s generally not that difficult to get enough Protein from your diet. Even on a Vegan or Vegetarian diet.
For the general adult population (under 65 years old) it is recommended you get at least 0.8g of Protein per Kg of bodyweight. Above 65 years this slightly increases to 1g per kg (1).
Babies and children require more Protein per Kg as they are growing rapidly, and one of Proteins main functions is growth and repair. Children from birth to 4 years old require about 1.3g of Protein per Kg (1).
Teenagers require 0.68g of Protein per Kg for females and 0.7g per Kg for males (1).
These values are the minimum amount required to prevent deficiency (which is pretty much unheard of in developed countries). You will require more Protein if.
- You are pregnant or lactating
- An athlete
- Recovering from illness
For people who are regular gym goers or who practice a sport, it is recommended to consume 1.2-1.7g of Protein per Kg per day (2) from the American Academy of Sports Medicine, or 1.8-2.7g of Protein per Kg (3) from the International Journal of Sports Medicine and Metabolism. So, which is right???
Basically, as long as you don’t exceed 3.5g of Protein per Kg of bodyweight there is no proof to say it would cause harm (4). In saying that there haven’t been many studies on the long-term effects of a high Protein diet either.
Studies have shown that most healthy individuals can tolerate up to 3.5g/Kg negative side effects. These side effects would include intestinal discomfort, nausea, diarrhoea, fatigue, irritability and dehydration (4).
Can A High Protein Diet Help You Lose Weight?
The answer to this question isn’t straight forward. As I mentioned above, Protein does provide calories, and like with calories from Carbs and Fat, if you don’t burn them, they are stored. Not as muscle, but as fat.
If you’ve ever heard me mention the hunger crushing trio of Fibre, Fat and Protein then you’ll know these nutrients take longer for our body to digest, this they keep us fuller for longer. This means you generally consume less food (in theory). Of course, this would usually then lead to weight loss.
If your simple cut back on calories with no thought to the individual nutrients you’re not likely to be successful in your weight loss journey. You’ll also be hungry, grumpy and you might even lose some muscle mass. Not good.
So yes, increasing the percentage of calories you get from Protein can help you feel fuller for longer after meals so you will generally consume less calories, and lose weight.
Of course, weight loss isn’t the same for everyone, but that’s a whole other article!
Does this mean you have to go Protein mad? No! Most people get more than enough Protein in their diet.
Here is an example to prove it!
So, for an adult who weighs 70kg the protein requirement would be at least 56g of Protein to 84g of Protein per day (58g for a sedentary person [0.8g x 70kg = 58g], 140 for a very active person [1.2g x70kg = 84g]).
| Breakfast | 2 boiled eggs 2 slices of wholegrain toast, buttered Tea with skimmed milk |
| Lunch | 1 medium tortilla wrap with chicken, cheese, BBQ sauce and a mixed salad 1 bag of cheese and onion crisps 1 cup of tea with milk 1 glass of water |
| Dinner | 1 portion of homemade chicken curry and rice |
| Snacks | 1 chocolate bar 1 fruit salad |
| Total Protein intake = 105g |
This offered more than enough for both the sedentary and active person. This example wasn’t a Vegan or Vegetarian diet, but it is also possible to get more than enough Protein from those diets too.
Sources of Protein include.
- Meat
- Fish
- Eggs
- Dairy
- Soy
- Legumes (Beans, Peas and Lentils)
- Nuts (especially peanuts, peanut butter is a great high Protein snack)
- Wholegrains
Are High Protein Diets Safe?
Like I said, they seem to be safe as, long as you don’t exceed 3.5g/kg, except if you have pre-existing kidney problems. There is no proof that a high Protein diet can cause kidney issues, but it does seem to negatively affect those with pre-existing kidney issues. The reason for that is a bit science. Basically, a Protein molecule differs from a Fat and a Carbohydrate molecule because it has Nitrogen. When you consume excess Protein, it is stored as fat, but Nitrogen can’t be stored so it is excreted through your urine, so through your Kidneys. Long term high Protein diet seems to negatively effect kidneys that are already no functioning optimally.
References
1. Richter M, Baerlocher K, Bauer JM, Elmadfa I, Heseker H, Leschik-Bonnet E, et al. Revised Reference Values for the Intake of Protein. Ann Nutr Metab [Internet]. 2019 [cited 2022 May 17];74(3):242–50. Available from: https://www.karger.com/Article/FullText/499374
2. Ormsbee DM, Barr C. ACSM Certification Blog and Articles [Internet]. ACSM_CMS. 2018 [cited 2022 May 17]. Available from: https://www.acsm.org/all-blog-posts/certification-blog
3. Hector AJ, Phillips SM. Protein Recommendations for Weight Loss in Elite Athletes: A Focus on Body Composition and Performance. Int J Sport Nutr Exerc Metab [Internet]. 2018 Mar 1 [cited 2022 May 17];28(2):170–7. Available from: https://journals.humankinetics.com/view/journals/ijsnem/28/2/article-p170.xml
4. Huizen J. How do you know if you are eating too much protein? [Internet]. 2018 [cited 2022 May 17]. Available from: https://www.medicalnewstoday.com/articles/322825
