For something as mundane as fuel for our bodies, food and our relationship with it are extremely complicated. Our nutritional knowledge is molded from birth. First, from our parents: Eat your greens! Drink milk for strong bones! No dessert until you clean your plate! In the tempestuous years of teenage rebellion, we do a 180 and discard the well-meaning advice of our elders and embrace the “coolness” of junk food and alcohol. At least I did. Some “Peter Pans” remain in the grips of the party food (pizza, sausage rolls, lemonade) beyond adolescence. Others make a transition to responsible adulthood by becoming your typical health conscious consumer. But most still continue to seek some authority to take on a parent role: government guidelines, scientists (as a vague joint body supposedly united by a common purpose and understanding), doctors, newspapers, weight loss shows, personal trainers, Sharon from next door because she has lost 7 kilos on the Lemon Detox diet. Once the authority figure is established, everything they say equals gospel and every decision you make is referred to their wisdom.
Here is a radical concept. You have a brain. So do I. I propose a framework. I will call it The Framework of Common Sense. Every time you hear of a new diet, new pill, new exercise regime, new wonder berry from Tibet, you apply the FCS and voila! Your rusty neurons spring into action. A word of warning though. FCS requires applying critical thinking to every new concept. Always. You can never turn your brain off and just go with the flow. If your attention is already starting to drift I suggest you go back to this.
This is where you ask yourself: does it make sense from physiological point of view? This one has a caveat: you have to know the basics of human biochemistry. Sorry.
Important things to know here:
A. Availability of mechanisms for digestion and absorption: is human body actually designed to process this food?
B. Nutrient density: does the diet in question provide enough vital nutrients for health without the need for supplementation?
C. Hormonal response: does the diet produce the hormonal environment necessary for everyday functioning and for special circumstances like growth, pregnancy, menopause, old age?
D. Inherent harm: can the diet cause damage to the body as suggested by biochemical mechanisms ?(note: do not confuse with Implied harm which is suggested by scientific evidence. It is further down the list)
STEP 2: Evolutionary environment
Is there evidence that people have consumed this food for a sizable chunk of human history? If yes, is there evidence that humans thrived on it?
Do not make your step 2 more important than step 1. Just because the food is ancient, it doesn’t mean it is automatically “good”. Australian Aborigines have been eating grubs and insects for thousands of years. I’m pretty sure that even if it turns out that cockroaches can cure cancer, they would never become a delicacy in the Western world. On the other hand, just because the food is modern doesn’t make it “bad”. Cheese is a modern food (and therefore off limits for the hardcore Paleo crowd). But step 1 tells you that cheese is A. Easily digested (unless people have specific issues with casein) B. High in essential fats, vitamin K, calcium etc. C. Has little effect on hormone levels D. Doesn’t cause inherent harm.
STEP 3. Scientific evidence
A. Implied harm: is there scientific evidence that the food or diet results in long term harm?
B. Implied benefit: is there scientific evidence that it is beneficial for health and longevity?
In science, the top level of evidence is a double-blinded multi-centre long term Randomised Controlled Trial (RCT). Two groups of people, similar in major demographics (age, gender, race, health status). The intervention allocated (in this case, a diet) is identical but for one variable. Neither investigators nor participants know the group allocation of an individual participant. Participants are followed up regularly and for a long time to assess risk and efficacy. You tell me if it is possible to test a diet using this principles.
The second tier in scientific evidence is observational studies. You select a group of people and observe their eating habits for some years and then record how many heart attacks, cancer, strokes etc. they get over the years. Or you ask heart disease patients about their dietary habits and then compare to healthy people. Or you do a national dietary survey and compare it to national disease statistics. Lots of loopholes in all of the above. Therefore…
Do not give step 3 higher priority than steps 1 and 2. Recognise limitations of scientific studies. For those who only trust scientific evidence, here is a nice review of the available evidence that the use of parachutes improves the outcomes of jumping off an airplane. Enjoy.
Now let’s apply the FCS to the Heart Foundation recommended diet (HFD)
STEP 1 Metabolism
A. Digestion and absorption
Major issue here is the massive content of so-called heart healthy whole grains. Your intestine is not a blocked pipe, it doesn’t appreciate being “scrubbed”. And to put it simply, if it comes out the other end in the same form as it goes into your mouth, it wasn’t meant to be digested.
B. Nutrient density
HFD is based on the concept that you can decrease the nutrient density as long as you have the same food volume. As a result you get skim milk, skinless chicken breasts, steamed watery vegetables and cardboard-tasting biscuits. Let alone a total lack of taste, how about the fact that cereals, breads, skim milk are so obviously devoid of nutrients that they have to be artificially fortified with thiamine, vitamin D, zinc, iron, etc.?
C. Hormonal response
55-65% carbohydrates? I don’t care whether you eat them on the form of sweet potato or Caramello Koalas, that’s a lot of insulin. If you are happy to pound the pavement for 10 kms daily and ruin your joints in the process just to control the fat-storing inclinations of that hormone, be my guest. And, guys, be prepared to do weight training every morning too, since insulin decreases testosterone concentration.
D. Inherent harm
3 words: wheat, fructose, hearthealthyindustrialvegetableoils (by the way, since when did canola and sunflower seeds get reclassified as vegetables?)
According to our algorithm we can stop right here. But let’s humour the zealots of conventional wisdom and work down the list.
STEP 2. Evolutionary evidence
7 million years of hominans. 2 million years of humans. 10 thousand years since some agriculture. 200 years of sugar. 50 years of industrial vegetable oils. Do the math.
STEP 3. Scientific evidence
Let’s face it: it’s very shaky. For a comprehensive analysis i.e. debunking of the lipid hypothesis (saturated fat raises your cholesterol, high cholesterol causes heart disease) please read this and this and this.
This algorithm can be applied to any nutrition plan: low-fat, low-carb, vegetarian, Paleo, vegan (horse-strength doses of vitamin B12 pills, anyone?), Jenny Craig and Raw food. I would love to hear some of you having a go at this algorithm. Or let me take on a diet or a food group of your choice.
The upside of using your own brain to make your own decisions is that you are in control of how you live your life. The downside is that you lose that wonderful sense of certainty that tends to come with ignorance. You will no longer be able just to trust media reports that start with the words “in the latest study the scientists have discovered…”. You will not be able to just accept your doctor’s advice to take the fat, salt and taste out of your food without asking WHY. You will have to know more about basic sciences, metabolism, anthropology, endocrinology, statistics and evidence-based medicine. You will have nagging doubts and constantly question yourself and others.
And if any of this is making you uncomfortable (quite understandable) it is never too late to turn back.