Two people can eat the same diet and have radically different results

In a Nutshell

  • Individuality is at the core of humanity and extends to differences in hormones, enzymes, and metabolism

  • There are proper individual diets but no such thing as a single proper human diet

  • One-size-fits-all approaches to nutrition, medicine, and overall health are flawed

 
 

I’m starting to read a book about how every human being is biologically unique - even identical twins are not identical at the molecular, biochemical, and physiological level [1].

Individuality affects the way we look, behave, and respond to the food we eat, sunshine exposure, and the pharmaceutical drugs we take. That last point is well understood (but sadly, not acknowledged) in the study of drug safety, the world I worked in for 30 years.

This means that "one-size-fits-all" approaches to nutrition, medicine, and public health generally are fundamentally flawed and often harmful.

Applying the concept of individuality to the world of nutrition, I’ll explore the following:

  • There is no single “proper human diet”

  • Conducting an experiment to find a proper individual diet – with n=1

  • A practical 3-phase protocol to find an individual diet

There is no single “proper human diet”

There is only a proper individual diet.

Anyone insisting there’s one true way for all humans (carnivore, vegan, Mediterranean, Paleo, keto, low-carb, whatever) either doesn’t understand basic human biology or is selling something. Some people thrive on rice and beans, others inflame on them. Some feel superhuman on steaks, others get constipated. The human species is not uniform.

That said, a few near-universal red flags do exist (in my view):

  • Seed oils (rapeseed (Canola), sunflower, soy, etc.) are harmful

  • Industrially processed food of any other kind is harmful

  • Vegan diets are bonkers – even its supporters admit it requires synthetic supplements

Conducting an experiment to find a proper individual diet

This is simply a way to test a dietary change on yourself and do so with an element of structure and discipline rather than just “winging it” as most of us (at least me) probably do most of the time.

Such experiments may be referred to as single-subject- or self-experiments. I use the term n=1 reflecting my background in the healthcare sector, where “n” is the number of participants in an experiment.

This is the approach to take when population studies can’t tell you what your body wants. Below is a simple, structured protocol.

A practical 3-phase protocol to find an individual diet

A protocol is just a fancy word for a plan. For this article, I’m drawing from a blog post I read recently. I liked the principles-led, structured approach the author advocates and which I have personalized below.

This approach can be used for anything a person wants to change. Many of my friends want to weigh less, so I’ll use that as an example.

Six principles to follow when designing an n=1 protocol.

  • Construct a baseline – this is a description of the present situation

  • Change one thing at a time – keep things simple in order to associate a change in diet with any measured outcomes

  • Measure the thing you want to improve – for example, weight, waist measurements, blood glucose (with CGM), energy, food cravings

  • Measure consistently the thing you want to improve – this allows detection of patterns which can be very revealing

  • Stick with it – continue long enough for results to emerge. Effects can appear in days (e.g., blood glucose as measured by a CGM) or weeks (e.g., weight, waist measurement).

  • Be safe – If anything makes you feel unwell, stop it and consult a doctor if necessary

Before contemplating how to construct a workable protocol, note the following:

  • I haven’t strictly followed the principle of Change one thing at a time. I believe that seed oils are so harmful that they should be eliminated from everyone’s diet. Their effects on weight gain likely take so long that including them in the experiment, in my opinion, is unlikely to be confusing

  • It is now well (if not widely) understood that a diet high in carbohydrates drives weight gain in many (most?) people. I tried to define carbohydrate diet types here. The protocol is, therefore, designed to understand an individual’s response to carbohydrate reduction

  • A continuous glucose monitor (CGM) is an invaluable tool to establish the effects of food on blood glucose. Use of a CGM is incorporated in the protocol

A practical 3-phase protocol for a n=1 experiment

Three, simple phases:

  • Establishing a baseline - your existing condition

  • Experimental Phase 1 - introduce a change and settle into a habit of observation

  • Experimental Phase 2 - determine what, if anything, the change you made results in

Baseline - 2 weeks

  • Wear a CGM to determine or confirm which foods cause your blood glucose to rise

  • Weekly - measure morning weight, waist circumference, or anything else

  • Daily – rate food cravings (1-10), energy (1-10), count number of meals and snacks

  • Eat and live normally, no changes yet

Phase 1 of experiment – 2 weeks

  • Eliminate seed oils – this applies to any experiment

  • Eliminate the single biggest carbohydrate source you believe causes your weight gain (this can be the processed carb you eat the most or the result of two weeks with a CGM). Common culprits include:

    • Breakfast cereal – cornflakes, Weetabix, coco pops, Cheerios, etc.

    • Bread, toast, croissants, bagels, donuts, etc.

    • Rice

    • Pasta

    • Sugary drinks, including fruit juices

  • Maintain calories - add in sources of protein, above-ground vegetables

  • Weekly – as above – these won’t change much, if at all in this time-frame

  • Daily – as above – you may well see changes here

  • Record-keeping – record everything – cravings (down) and energy (up) change fast

Phase 2 of experiment – 3 months

  • Keep everything from Phase 1

  • Weekly – weight and waist measures will be seen here if the new diet works

  • Daily – improvement may continue

  • Record-keeping – keep up the detailed notes

When Phase 2 is completed, you’ll have collected valuable information that will help determine next steps:

  • If you lost weight, felt better, and cravings vanished, you’ve improved your individual diet. Lock it in as your new baseline.

  • If nothing much happened, pick a different carb category to eliminate and repeat the experiment

  • If you felt worse, reintroduce the removed food and repeat the experiment with something else

Summary

Congratulations for trying something radically different. Don’t underestimate how difficult this process may be. Changing dietary habits isn’t easy, especially if you’re suffering from even mild food addiction. As I’ve said before:

 
Modern food is laden with hidden sugars and starches, leading to chronic health issues. By recognizing the addictive nature of high-carb foods and making intentional dietary changes, I have broken free from the cycle of cravings and poor health. Reducing bioavailable carbohydrates, eliminating processed foods, and focusing on nutrient-dense whole foods is, in my opinion, the key to long-term wellness.
 

As always, heed your doctor’s advice, if necessary, especially if you’re on medication.

Finally, never forget [1]:

 
Nutrition is for real people. Statistical humans are of little interest
 

When done properly, the results of an n=1 experiment are likely to be positive. After all, the only expert who lives in your skin is…you!

References

1. Williams, R.J. (1998) Biochemical Individuality: The key to understanding what shapes your health. New Canaan: Keats Publishing, Inc


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