Why Your Friend Thrives on Keto (and You Don't).

The forgotten aspect of your metabolism that determines which health advice works for you. And, which advice doesn't.

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Supporters of this publication will know that for over a year I have been deeply studying the school of medicine which arose from the ancient Greeks. This school has been built upon by various societies from around the world since its origination with the likes of Galen and Hippocrates.

This is the Unani (Greek) school. The source I began to read was the encyclopedic work of Avicenna’s Canon:

The Law of Natural Healing | Part 1

I’ve since written 5 parts to this series, and decided to take a break from the encyclopedia to more thoroughly explore the concept of temperament.

The more I learn and think about temperament, I am in perpetual awe of its power and simplicity. As time goes on, I’ve realized that understanding your temperament is the unlock that everyone has been waiting for.

Everyone that has tried the latest guru-sponsored diet, supplement or routine…and has gained less than expected results…will find this helpful.

The latest health fads have a tendency to exaggerate the impact of their shtick by focusing on those for whom it works, and ignoring/downplaying those for whom it doesn’t.

But, we really need to linger on this point.

Why doesn’t this miraculous health practice not work for everyone?

Is it “genetic?”

Maybe.

More than likely, however, it is temperamental.

Not the pseudo-psychic kind of temperament. But, the complete body/mind/spirit kind of temperament.

So deeply do I believe in the power of knowing your temperament, I created a brief 5-minute quiz you can take to know your dominant temperament:

Temperament: Why Your Body Responds Differently.

Now, of course… it is not as simple as just knowing what your dominant temperament is. There are sub-dominant, and co-dominant temperaments that also play a role depending on which aspect of your life (or part of your body) you are trying to optimize.

Moreover, even once you know your temperamental composition…

What are you supposed to do with this information?

In this article, I want to use the example of my own temperament to illustrate how it can/has guided my lifestyle choices.

My Temperament

When I took the temperament quiz (link above), I was given a pretty resounding result: Dominant Sanguine, sub-dominant phlegmatic.

In the Unani parlance, this would simply be referred to as Sanguine-phlegmatic.

A brief sketch of this temperament:

Meet someone with the Sanguine-Phlegmatic temperament, and you’ll immediately notice their warm, infectious energy. They light up rooms with genuine enthusiasm and have an almost magnetic ability to make others feel welcome and valued.

Unlike their purely Sanguine cousins who can bounce endlessly from one activity to the next, the Sanguine-Phlegmatic person carries a quieter wisdom.

Their bodies tell the same story of duality. They run warm and energetic, often the first to suggest a spontaneous outing or try a new restaurant. Yet they also carry the Phlegmatic tendency toward weight gain and need more recovery time than their energy levels might suggest.

They might throw themselves into a new fitness routine with characteristic Sanguine enthusiasm, only to burn out within weeks because they ignored their Phlegmatic need for gentler, more sustainable approaches.

Spring energizes them almost to the point of overwhelm, summer finds them at their most social and vibrant, fall grounds them into cozy contentment, and winter calls them toward rest and reflection in ways that might surprise those who only know their sunny exterior.

The challenge for Sanguine-Phlegmatic individuals lies in honoring both sides of their nature—feeding their need for joy and connection while respecting their deeper requirement for peace, routine, and adequate rest. When they achieve this balance, they become the steady optimists of the world: reliable yet spontaneous, energizing yet calming, the kind of people who make life feel both exciting and safe.

Many people who took this quiz are either Sanguine or Phlegmatic, so they may resonate with some of these points.

This captures many, but not all aspects of my being. As earlier in my life, I had more choleric aspects to my temperament as well…but, these have since evolved into adulthood and fatherhood.

Seasonal Sketch of the Sanguine-Phlegmatic

I’m a 34 year-old doctor with a wife and two toddlers, with a third one on the way. We live in the south, and have long, hot and sometimes humid summers.

Sanguine: Hot-wet, likened to the Spring

Phlegmatic: Cold-wet, likened to the Winter

We will now explore day-to-day life as it varies through the season, highlighting:

• Mistakes I’ve made in the past

• Changes to my life that have helped

• Things which I plan to implement

Spring: Awakening and Renewal

Mistakes:

• Jumping into intense workout routines that burned me out in a few weeks

• Eating raw salads and drinking cold smoothies

• Over-scheduling life/work/social activities

• Forgetting to adjust my days routine as Winter waned

• Ignoring body’s natural elimination rhythms as the season transitioned

Changes that helped:

• Wake up naturally with the sunrise, ideally 30-60 minutes before the Sun

• Wind-down after sunset, reading, stretching

• Bedtime about 2 hours after sunset, 8 hours of sleep is optimal

• Get outside for morning fresh air and rising sunlight

• Gentle morning activity

• Avoid cold food/beverages in the morning

• Consume gently warming foods and beverages

• Avoid high-intensity training and competitive sports

• Instead focus on moderate activity like bike rides, whole-body exercises, and just trying to keep up with the kids

Why: Spring’s natural warming can overheat a Sanguine, so we avoid intensely hot consumption and intense activity. The Phlegmatic needs elimination support to prevent sluggishness. Optimization of elimination and detox pathways are crucial.

• Declutter - aligns with Sanguine need for Spring cleaning

• Organize outdoor spaces and manage yard/garden for family and gatherings

• Open windows for fresh air and natural light

• Set plans for new projects as Spring is the time for abundant growth

Plan to Implement:

• Focus on family connection and community building

• Avoiding overcommitting to new obligations and schedules

• Incorporate calming activities, as both my Sanguine and Choleric side yearn for excitation

• Ensure adequate hydration - I’ve always been bad at this, which is common for Phlegmatics

• Maintain consistent sleep schedule - this is always difficult with changes of toddlers, newborns, and work schedule.

Summer: Peak Energy and Social Connection

Mistakes:

• Too many cold foods and iced drinks → disrupts digestion

• Staying up late for social events

• Disrupting sleep cycle

• Vacations disrupting diet and sleep

• Travel/Vacation can lead to exhaustion, we’ve all been there

• Too many events can do the same

Changes that helped

• Greek yogurt with fresh fruit and honey for breakfast

• Leaner protein

  • Consuming beef/steak is intolerable in the summer

  • Side note: many of my carnivore colleagues have reported a similar experience

• Cucumber and watermelon to both cool and moisten in the hot dry of the summer

• Summer’s bountiful herbs for digestion and detox

• Adequate salt for hydration

• Avoid alcohol, spicy foods, and heavy meats

• Swimming or water related activities

  • allows you to stay active without overheating

• Outdoors as much as possible, where there is shade even better

Are you sure this is unique?

If you are being objective and critical, you may say something like:

This sounds great. But, these dietary requirements generally sound like good healthy habits for everyone...

A reasonable objection, no doubt.

I think it would be helpful to compare this with a different temperament.

For example, let’s compare the Sanguine-Phlegmatic to a Melancholic-Sanguine person.

Using the Winter season for comparison, let’s look at dietary recommendations.

Sanguine-Phlegmatic: The heat of the Sanguine balances Winter nicely. However, in combination with the Cold/Wet Phlegmatic (remember the Sanguine is also wet), they run risk of becoming sluggish to digest and prone to weight gain.

This person requires warming foods which are light. Light stews with plenty of vegetables, warming spices like ginger and cinnamon, and herbal teas. Take care with rich, heavy foods that the Phlegmatic side can’t process efficiently.

In contrast, the Melancholic-Sanguine: The winter can be the most challenging season for this person. The Cold-Dry constitution can be compounded by winter’s cold, while the Sanguine secondary needs warmth and richness. This person thrives on the very foods that would slow down the Sanguine-Phlegmatic: rich bone broths, hearty stews with healthy fats, warming spices in abundance, and even heavier proteins like lamb or beef. The dryness that comes with the Melancholic needs more oils and fats, while the Sanguine warmth helps digest these richer foods.

Though the differences may seem subtle, they are important.

The Sanguine-Phlegmatic challenge is avoiding sluggishness, while the Melancholic-Sanguine challenge is preventing energy/resource depletion. Same season, but one needs stimulation without heaviness while the other needs substantial nutrition.

This doesn’t just apply to diet, of course.

Another Pillar of health is activity, and this is also influenced by temperament.

Let’s compare the Sanguine-Phlegmatic to a Melancholic-Choleric person with respect to their exercise needs in the Winter.

The Sanguine nature craves movement and social connection, but the Phlegmatic component creates a natural inclination toward hibernation and rest. In winter, this person needs gentle, warming activities that stimulate circulation without depleting energy reserves. Light, indoor, and social forms of activity are preferred for this person.

In contrast, the Melancholic-Choleric must use winter exercise as medicine against seasonal depression and energy loss. The melancholic constitution becomes dangerously stagnant in winter, while the Choleric fire provides the internal drive to push through when motivation is low. This person needs more intense, heat-generating activities—vigorous indoor cycling, hot yoga, or strength training that builds internal fire in the cold Winter.

I think you get the point…

We could go on about these differences until the cows come home.

There are 4 temperaments, each present in varying proportions from person-to-person, the composition of which influence the habits/lifestyles that are optimal for any given person.

This is why I continue to hammer home the basis of the Foundational Health approach: know thyself.

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I’m pleased to see the temperament self-assessment getting so much use and generating helpful feedback.

I hope that within the next month or two, I will have a fully developed quiz that will provide a more thorough assessment of your temperamental composition (not only the dominant temperament), and some useful information to lead you down the right path of optimizing your health.

Don’t forget to subscribe to keep abreast of all developments.

In other exciting news, this project has generated enough revenue to hire the help of a professional team to solidify the design/appearance of my work, especially as we move towards launching the podcast.

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And Finally, I will be away from the computer for the next 7-12 days.

I’ll be taking my father and brother on an extended Western backcountry hunt.

Wish us luck!