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Welcome to Weekly.health’s 27th issue. Every week, we explore cutting-edge research, actionable advice, and science-backed nutrition insights to help you live longer and healthier.

Our aim is to help you live another 10 healthy years and cut your risk of age-related disease.

🗒️ In This Issue:

• 📚 A brief note

• 📚 Books We’re Reading Right Now

• 📈 Research Digest: What’s new in nutrition science

• 🔥 Calculate your BMR (try our free tool)

• 🔥 How many calories should you eat? Calculate your TDEE (and why it matters)

• 🛍️ Recommendations

• 📘 Glossary of Terms: Definitions for technical terms in this issue

📚 A brief note

Weekly.health has been around for more than 6 months, and we wanted to share a quick, honest update.

From the outside, it’s reasonable to assume that a newsletter like this — with affiliate links, book recommendations, and now educational tools and courses — comfortably pays for itself.

In reality, it doesn’t. In practice, each issue currently generates only a small amount of revenue - often around £5, and sometimes less - yet costs significantly more to produce.

Each issue takes several hours of research, reading, and synthesis, and while revenue has slowly increased, Weekly.health still runs at a net loss per issue once platform costs and research tools are accounted for. We’ve worked hard to streamline production and keep costs sensible, but growth itself increases those costs faster than it increases revenue.

The newsletter isn’t going away, and we’re committed to keeping it independent, evidence-based, and accessible, but our goal during 2026 is to make it sustainable to run. If you find value in the work and would like to help make it sustainable, one simple way to do so is via Buy Me A Coffee. Even a single coffee genuinely makes a difference.

There’s absolutely no expectation — your time and attention already mean a great deal. We’re grateful you’re here.

You can still support us by selecting from our recommended books and products below.

📚 Books We’re Reading Right Now

📈 Research Digest: What’s New in Nutrition Science

Here’s the best of recent nutrition research:

🧬 NAD supplements show promise in rare premature ageing diseases
A major review found that boosting NAD (often via nicotinamide riboside, ~500–1000 mg/day) improves DNA repair, mitochondrial health, and symptoms in rare genetic conditions like Werner syndrome and ataxia-telangiectasia. Small human trials showed better vascular health, coordination, immunity, and wound healing, with few side effects. This suggests NAD may help people with high DNA damage and potentially inform healthy ageing research. (source)

❤️ Beetroot + vitamin C may improve heart health markers
In a 4-week trial of adults with chronic coronary artery disease, taking beetroot extract (1,500 mg/day) improved oxidative stress and fatty acid balance, especially when paired with vitamin C (100 mg/day). The combo raised omega-3 levels (including DHA), lowered harmful fat ratios, and reduced myeloperoxidase, a marker of artery inflammation. Beetroot alone helped too, but vitamin C amplified the benefits. (source)

😴 Certain supplements genuinely improve sleep (but not all equally)
A large meta-analysis of 28 randomised trials found dietary supplements modestly but meaningfully improved objective sleep. On average, supplements increased sleep efficiency by ~2.6%, added ~16 minutes of total sleep, reduced time to fall asleep, and cut night-time awakenings. The strongest evidence supported tryptophan, vitamin D, omega-3s, zinc, magnesium, and antioxidants. Self-reported sleep improved less consistently, but physiological sleep clearly benefitted. (source)

⏳ Intermittent fasting cuts harmful blood fats even without “clean eating”
In a 6-month randomised trial, overweight adults followed intermittent fasting (2–3 non-consecutive veg-only days/week, ~500 kcal). They lost ~8% body weight and reduced non-HDL cholesterol by 11% and triglycerides by 25%, despite eating a typical Western diet on other days. Blood sugar, blood pressure, and inflammation didn’t change, but cholesterol risk clearly improved. (source)

🔥 Calculate your BMR (try our free tool)

Do you know how many calories your body needs just to exist?

Your basal metabolic rate (BMR) is the number of calories your body burns each day at complete rest — breathing, circulating blood, maintaining organs, repairing cells. No steps. No workouts. Just staying alive.

Why does this matter?

Because BMR is the foundation of almost every nutrition decision:

• Trying to lose fat without under-fueling

• Eating enough to support muscle, hormones, and recovery

• Avoiding “mystery plateaus” where weight or energy stalls

• Understanding why two people of the same size can need very different intakes

If you don’t know your BMR, you’re guessing, often by hundreds of calories per day.

I’ve just calculated mine using our BMR calculator over at The Healthspan Academy BMR calculator (screenshot above). It takes less than a minute and gives you a personalised baseline you can actually use, whether your goal is fat loss, muscle, or long-term health and longevity.

Once you know your number, everything else - protein targets, calorie ranges, even meal planning - becomes clearer and far easier to get right.

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🔥 How many calories should you eat? Calculate your TDEE (and why it matters)

If you’ve ever wondered “How many calories should I actually be eating?”, your TDEE is the best starting point.

TDEE stands for Total Daily Energy Expenditure. It’s an estimate of how many calories your body burns in a typical day, including:

• your baseline “keep the lights on” energy use (BMR, basal metabolic rate)

• plus everything else: walking, fidgeting, training, work, digestion, and recovery

Why knowing your TDEE is so useful

1) Fat loss becomes predictable (and less miserable)
Instead of guessing, you can choose a measured deficit that supports adherence, training, and sleep, which is where most “fat loss plans” fall apart. For the majority of us, it’s as simple as consuming fewer calories than your TDEE.

2) Muscle gain is faster with less fat gain
A small surplus beats a huge one. TDEE gives you a reference point so you can add enough fuel to grow without accidentally turning it into a bulk you regret. Similar to fat loss but in reverse, for most of us gaining muscle requires consuming more calories than your TDEE, alongside the right combination of macronutrients and exercise.

3) Better performance, recovery, and healthspan
Chronic under-eating can quietly sabotage training output, mood, libido, and sleep. Over-eating can creep up on you just as easily. TDEE helps you steer between the two.

4) It makes your nutrition “data-driven” without becoming obsessive
You’re not trying to be perfect, but you’re trying to be consistent and get feedback from reality.

Step-by-step: calculate your TDEE with our tool in 60 seconds

1. Enter your basics
   Add your height and weight (kg (lb)) plus the usual details (age, sex). This gives your BMR estimate.

2. Choose the activity level that matches your real week
   Be honest here: most errors come from overestimating activity. In our calculator you can pick from:

• Sedentary (mostly sitting, little intentional exercise)

• Lightly active (some walking, light exercise 1–3 days/week)

• Moderately active (more daily movement or training 3–5 days/week)

• Very active (physically active job and/or hard training most days)

• Extremely active (athlete-level volume or very physical daily work)

3. Get your TDEE + goal targets
   You’ll see your maintenance calories, and handy “what to do next” targets (e.g., a sensible deficit for fat loss, or a surplus for muscle gain).

4. Treat it as a starting point, then calibrate for 2–4 weeks
   Even good calculators are still estimates. Your true maintenance can vary because of genetics, muscle mass, day-to-day movement, and metabolic adaptation.
   

   The easiest way to dial it in:

• Track intake consistently (even roughly)

• Weigh yourself 3–7×/week, then look at the weekly average

• If weight is stable, you’ve found maintenance

• If weight is drifting, adjust calories in small steps and reassess.

➡️ Try it now: head to TDEE Calculator inside The Healthspan Academy to calculate your maintenance calories and set a goal target in seconds.

🛍️ Recommendations

Discover the products, services, and retailers we’ve mentioned in past Weekly Health issues, all in one place so you can explore at your own pace.

📥 Finding this newsletter useful so far?

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🙏 Thanks for Reading!

That’s the end of this issue of Weekly.health.

This newsletter is written by a small, independent team, led by James — who’s been following nutrition science for nearly 20 years and is now working towards a formal, industry-recognised qualification.

We’re based in England, so if you’re over the pond, you might notice a few strange spellings.

Our goal is to make cutting-edge, evidence-based nutrition advice simple, useful, and genuinely applicable to everyday life.

We don’t want to bombard you with adverts, but a few of the links in this email may reward us when you click and make a purchase. This goes towards helping us to continue bringing you this newsletter.

We’ll keep improving with every issue. If you’ve got any feedback or suggestions, we’d love to hear them (just reply to this email).

See you next week!

📖 Glossary of Terms in This Issue (Alphabetical Order)

A–Z Glossary of Technical Terms

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