Protein Requirements, Nutrition Myths and More with Chana Davis
I recently got the opportunity to sit down with Chana and chat about nutrition. Chana has a background in genetics and loves to dig through the data to uncover the facts. She loves debunking nutrition myths and getting clear answers in a field that can be very confusing. I really enjoyed this chat and hope you will too.
If you like what you read below, you can read more articles written by Chana in resources outlined at the end of this interview.
A little bit about Chana
After getting her undergrad in genetics in Vancouver, Chana received her PhD from Stanford. She worked for 10 years in biotech and medical research and recently made the switch to following her passion of helping people making informed healthy decisions amidst the onslaught of misinformation.
Clem: What do you think is the biggest misinformation out there concerning nutrition?
Chana: Oh boy… it’s hard to choose just one thing! These days, I’m fixated on setting the record straight on sugars. There is a common misconception that ‘raw’ sweeteners such as honey, maple syrup, and agave are better for you than table sugar. The reality is that body can’t tell the difference between them. They are all the same at a chemical level – they are all made of glucose and fructose (sucrose is just glucose and fructose joined together). In fact, the ‘odd man out’ of this bunch is agave, which stands out as having far more fructose than the others (and less glucose), but the jury is still out on the health impact of too much fructose. The amount of sugar and the package it comes in (solo or with fiber, like in fruit) matter more, than whether it comes from bees or trees or sugar cane or corn. I think a lot of the misconception boils down to what’s known as the ‘naturalistic fallacy’ – the belief that is anything natural must be good for you, and that anything made in a lab must be bad. Neither belief is supported by science. Sorry for the rant, that last a long answer to a supposedly simple question!
Clem: what is the best thing people can do to avoid being misled?
Chana: There are 3 things I recommend doing to boost your anti-hype armour.
The first is to apply the ‘fact check’ filter. If you read a claim that something is good or bad for you, but there is no scientific study that you can use to check the “facts”, that’s a big red flag.
The second thing is to learn about the scientific evidence hierarchy or totem pole. I tend to only pay attention to studies that are at the top of the totem pole. I’m talking about the ‘gold standard’ of science: large, placebo-controlled, randomized human trials. Most nutritional studies are much lower on the totem pole, such as experiments on cells in a lab, experiments in mice, and ‘observational’ human experiments where you simply compare groups of people with one diet to those with another.
The third thing is to learn the difference between correlation and causation. Just because obesity rates went up from 1970-2000 at the same time as high-fructose corn syrup consumption went up, doesn’t mean you can say that the corn syrup caused it. Bottled water consumption went up at the same time, and you can be pretty sure that bottled water didn’t cause it!
Clem: When I look at food labels, what is RDA and how is it measured?
Chana: RDA stands for recommended daily allowance. It represents the amount of a given nutrient that should meet the needs of 95% of the population.
Clem: who would be outside that 95th percentile?
Chana: depending on the nutrient, those that have very unusual body composition, or very unusual levels of activity could be an exception. For example, bodybuilders could be an exception for protein needs.
Clem: should people worry about their body type? Being either a mesomorph, endomorph or ectomorph?
Chana: Not really. The 95th percentile is reported exactly for that reason - to be generous. So, mesomorphs, who may have more than average body protein should be diligent about getting the RDA, whereas a less muscular body type probably can get away with less than the RDA.
Clem: so the big question is how much protein do people need?
Chana: For adults, I recommend about 0.5 grams of protein per pound of body weight, which is higher than the official RDA of 0.38 grams per pound. The answer is the same for men and women. To figure out your needs, take your weight in pounds and divide by two - for example, if you weigh 140 pounds, you will be well off at 70 grams of protein per day.
I want to add that children need somewhat more than adults do, because they are growing. For children, take weight in pounds and multiply by 0.7 to get the number of grams. For example, my son’s target is 42 grams per day based on 60 lbs x 0.7 grams per pound. I recently published an article on children’s protein needs:
The official RDA comes from a large number of studies that used a tried and true method called Nitrogen Balance. To make my recommendations, I looked at these studies but also looked at a few recent (small!) studies using different method called Indicator Amino Acid Oxidation.
I should add that some elite athletes may benefit from slightly more than this – particularly bodybuilders. They may want to be in the range of what growing children need (0.7-0.8 grams per pound). There is no evidence of much benefit beyond this, though in severe calorie deficits, more protein can help stave off muscle wasting.
At extremely high levels, it can be taxing on the liver and kidneys and lead to inflammation. Some longevity researchers believe that too much protein is associated with faster aging, and that this is one of the reasons that fasting promotes longer lifespan. Last but not least, going nuts for protein can be very restrictive and limit the joy of healthy eating!
Clem: You mentioned nitrogen balance, what’s that?
Nitrogen balance: Unlike fats and carbohydrates, proteins contain the element nitrogen. Each day, we take in nitrogen from the proteins in our food, and we lose nitrogen – mostly from urine, but also from other sources (sweat, feces, dead hair). We also do a lot of nitrogen recycling inside our bodies. In adults, we want to be in nitrogen balance, which means that we should take in as much as we lose. Nitrogen balance studies measure both the intake of nitrogen and the loss and figure out what level of intake produces a balance. The story is a little different with children, because they are growing – they need to take in more nitrogen than they loose, something called positive nitrogen balance.
Clem: Without having to measure their food, what can people do to make sure they are getting enough protein?
Chana: it really helps to learn some rules of thumb about protein content. Most whole foods have ample protein so if you fill up on these, you should be in good shape. Fruits and oils are the big exception, they are low in protein. Processed foods are often low in protein (relative to total calories) because they have a lot of added fats and sugars. Those with exceptionally high needs, like bodybuilders, will obviously need to skew their choices even further towards high-protein foods and away from low-protein foods. I talk about a simple holistic approach to getting enough protein in one of my articles:
Clem: is there such a thing as an incomplete protein?
Chana: I’m glad you asked. The myth about plant proteins drives me nuts – to the point where I wrote an article about it!
The bottom line is that the proteins in plants are made up of the same 20 amino acids as animal proteins. So, while individual purified proteins (such as collagen) don’t use all 20 amino acids, if you eat a whole organism, whether plant or animal, you are going to get all 20 amino acids. Some fruits are an exception, but if you are counting on fruit to get your protein, you are in trouble!
Clem: what is the biggest mistake people make when it comes to nutrition?
Chana: going too extreme one way or another. Any extreme diets or methods are not sustainable and do not support long- term goals. Eating too much processed food and not enough whole foods is another all-too frequent mistake.
Clem: What is your biggest recommendation?
Chana: Fill your plate and your tummy with whole foods. This is the easiest way to achieve good health without needing to do any tracking. That said, if you’re a data geek like me, or simply want peace of mind, try out an app to see how you’re doing for a while. These tools can be especially useful for vegetarians or vegans to figure out whether or not they need to supplement.
I recommend My Fitness Pal and Cronometer - Cronometer is especially good for tracking micronutrients.
To get more of Chana’s insights on nutrition (and fitness!) check out:
Hope you enjoyed the chat!