The 6-Week Diet Swap That Changed Everything

Sometimes the smallest tweak has the biggest ripple.
A recent study from the University of Helsinki found that men who simply swapped part of their red- and processed-meat intake for legumes lost weight, improved cholesterol and did it without cutting calories.

No crash diets in sight or any fancy fasting protocols. Just some variety with protein sources.

The study

Fifty-one Finnish men aged 20 to 65 cut their red and processed meat down to about 200 g a week; roughly two sausages and a slice of bacon.

They replaced that protein with peas and fava beans, keeping chicken, fish, and eggs as usual.

That was it! No specific instructions to eat less.

After six weeks, the men were one kilo lighter on average, had lower total and LDL cholesterol, and better iron levels… despite eating less red meat.

The control group; men who kept eating meat and skipped legumes… lost almost nothing.

Why the change worked

It wasn’t magic beans that changed the game…it was metabolic mechanics.

1. Satiety: Legumes are packed with soluble fibre and resistant starch, which slow digestion and trigger fullness hormones. You naturally eat less… even if you’re told not to.
   

2. Microbiome metabolism: That fibre feeds gut bacteria that produce short-chain fatty acids (SCFAs) like butyrate, which help regulate appetite and fat storage.
   

3. Cardio-metabolic health: Swapping processed meat (rich in nitrates and saturated fat) for legumes lowers LDL cholesterol and inflammation… two key risk factors for heart disease.
   

4. Iron surprise: Plant-based diets can still deliver iron if paired with vitamin C-rich foods. In this study, men’s iron levels actually improved, likely because their guts became more efficient at absorbing nutrients.
   
   

What you can take away

You don’t have to go vegan (unless you want to). You just need to diversify your protein sources.

Try this for six weeks:

• Replace two red-meat meals a week with lentil, chickpea or bean-based dishes.
  

• Add peas or edamame to stir-fries or salads.
  

• Blend half minced meat, half lentils for chillis or bolognese.
  

• Pair plant proteins with vitamin C (tomatoes, peppers, citrus) to boost iron absorption.
  

• If you’re worried about bloating, introduce legumes slowly… your microbes adapt within days.
  
  

Even that modest shift can recalibrate your microbiome, reduce inflammation, and lighten the scale without restriction.

Men are twice as likely as women to exceed red-meat guidelines. Cutting back doesn’t just protect your heart but it’s also a small step for the planet.

Microbiome minute

Each legume species feeds different gut microbes:

• Lentils → boost Faecalibacterium, a major butyrate producer.
  

• Peas → feed Bifidobacteria, linked to lower inflammation.
  

• Fava beans → increase Akkermansia, tied to metabolic health.
  
  

So variety really matters.

P.S: This is exactly why I built LOAM …a product that comes as close as possible to recreating a diverse and varied diet in the form of a multi-fibre prebiotic blend. Something designed to feed your existing good bacteria on the days you don’t hit your fibre target. Travel, takeaways, or missed meals… or just as a daily ritual, LOAM  keeps your gut ecosystem thriving. It’s out in around 3 weeks time, so if you want to be first to get some, join the waitlist here:

(I’m always giving away some waitlists only exclusives!)

Four Science-Backed Ways to Get Deeper Sleep (That Don’t Involve Melatonin)

Sleep advice is usually terrible.
“Just relax.” “No screens.” “Drink lavender tea from the tears of Himalayan monks.”

Let’s skip the wellness woo and talk about what the science actually says works… things normal humans can do tonight that genuinely deepen slow-wave, restorative sleep.

1. Take a hot bath before bed (+18 mins deep sleep)

A 10–30 minute soak at ≈ 40 °C, about 90 minutes before lights-out, raises your core temperature.
As you cool afterwards, the body interprets that drop as a signal to sleep… like hitting your internal “night-mode.”

A meta-analysis found passive body heating adds 13–18 minutes of deep sleep.
Think of it as biohacking by bathtub.

Tip: Don’t hop in too late or you’ll overheat. Finish your bath an hour before bed.

2. Sleep cooler (+14 mins men / +9 mins women)

In a one-week study of 54 people, those using a temperature-controlled mattress spent significantly longer in deep or REM sleep.

Cool skin + stable core temp = less tossing, more restoring.

If you don’t have a smart mattress, open a window or set your room around 18–19 °C.

3. Eat more fibre (+18 mins deep sleep)

The most boring nutrition advice strikes again.
In one study, high-fibre eaters logged 18 minutes more slow-wave sleep versus low-fibre eaters. High saturated-fat diets lost 11 minutes.

Fibre steadies blood sugar and feeds gut microbes that make short-chain fatty acids, which in turn support steady brain-wave activity overnight.

Actionable swaps: Add beans, oats, lentils, or even a fiber supplement.
And yes your gut and your brain gossip all night long.

4. Try “pink noise” (+12–15 mins deep sleep)

Pink noise (think rainfall or ocean hum) boosted slow-wave activity by 8 percent in a sleep-lab study of older adults. It’s gentler than white noise, syncing brain rhythms into deeper sleep stages.

How: Spotify, YouTube, or any free app; set it low enough that you don’t notice it after 5 minutes.

Why this all works together

Deep sleep isn’t one lever but a large complex system.
Temperature, diet, sound, and gut health each tweak how your brain cycles through stages. The more signals you send that say “it’s safe, calm, and nighttime,” the more restorative your sleep becomes.

My favourite combo: Hot bath → cool room → fibre-rich dinner → pink-noise playlist.
Simple, boring but ridiculously effective.

(PMID: 12379298, 38671774, 26156950, 28337134)

Quick interlude: If you think The Weekly Dose is cool 😎, share this newsletter on socials, mention it in your newsletter, and/or hit forward to your health-curious friends, family, and that one fiendish coworker who loves learning about health stuff.

Reminder: This newsletter is free, always will be and I send it out every Sunday to give you in-depth insights into the health topics!

The Snakebite Principle:

How to stop overthinking before it poisons your day

Imagine you’re walking through long grass and a snake snaps at your ankle. You feel the puncture, the burn. What do you do?

Most of us know what to do: pressure, immobilise, get help. But the overthinking brain does something else:

“Was it a viper or a cobra? How long are its fangs? What’s the Latin name? Should I compare hospital reviews first? Maybe watch a video on venom pathways…”
Meanwhile, the venom spreads.

That’s overthinking: compulsive taxonomy while the toxin circulates. It feels smart…curious, thorough, responsible. It is, in fact, a delay tactic dressed as diligence.

Your brain loves the dopamine drip of information more than the discomfort of action. Reading, planning, collecting opinions… these deliver tiny rewards that mimic progress while your situation quietly worsens. 

In clinic, we call this the difference between stabilisation and speculation. First you stop the bleed. Then you write the essay.

The snakebite principle

When stakes are real and time is leaking, act on the best 70% you know and earn the rest through feedback. Anti-venom beats an annotated bibliography.

Here’s how to apply it when your mind wants to scroll instead of solve:

1) Identify the venom.
Name the actual threat in one sentence: “I’m avoiding sending the proposal.” “I’m not starting the workout.” If you can’t name it, you can’t dose it.

2) Do the next necessary thing.
Not the perfect thing. Not the final thing. The next thing.

• Proposal → open the doc and write the first three lines.
  

• Workout → shoes on, 5 minutes of movement.
  

• Tough conversation → draft the first honest text.
  
  

3) Use the reversibility test.
If a choice is reversible (most are), you do not need complete information. Move. Save your deep analysis for irreversible moves (resignations, contracts, surgery).

4) Set a five-minute tourniquet.
Five minutes of focused doing: timer on, phone away. Momentum is antivenom. You’ll often continue after the timer because motion manufactures motivation.

5) Limit the venom source.
One screen. One tab. One question: “What produces progress in the next five minutes?” Everything else is snake trivia.

Yes, research and information gathering is important…

…after you’re stabilised. In medicine, we don’t Google the venom while the patient’s airway collapses. We secure the airway, then we open the textbook. Sequence matters. Overthinking is usually a sequencing error.

You don’t need to become fearless but simply become more sequenced. Act, then analyse. Move, then refine. Most of life’s “snakes” aren’t lethal but the habit of delay can be.

👋 Who are you again? I’m Karan Rajan - a doctor and curious explorer of all things health and wellness. I host the Dr Karan Explores Podcast and have written two books "This Book May Save Your Life" and "This Is Vital Information" (you can pre-order it now!) and have just founded a microbiome company, LOAM Science  to create the best fiber product in the world!

Every Sunday, I share 3 interesting things about health, life and science to make your life easier, healthier and happier. (Disclaimer: I’m more your friend with health benefits. None of this is medical advice.) 

And oh, you if also feel strongly about some health things or just want to say hi? Hit reply... I’d love to hear it and hear from you! (yes I read every reply!!!)

Oh and before you wiggle away until next Sunday… here’s the subscribe link to my newsletter if you fancied sharing it with a friend, family member or your arch nemesis!