LampHill Letter: June 2026

This month covers two contested nutritional orthodoxies, the RDA for protein and the calorie-versus-timing debate, alongside a closer look at what GLP-1 drugs are doing to muscle. The brain's overnight waste-clearance system and the underappreciated breadth of creatine's evidence round out a month heavy on fundamentals.

This month's reading

Longevity. The case for eating windows rests on when mattering as much as how much, but does the evidence hold up? Does time-restricted eating beat calorie restriction, timing vs amount

Cardiovascular. GLP-1 drugs have drawn more coverage than almost any drug class in memory, and muscle loss is the part getting less attention. GLP-1 drugs, miracle or crutch (and the muscle-loss problem)

Brain. Your brain runs a dedicated cleaning cycle during sleep, and knowing how it works reframes what disrupted sleep costs. Glymphatic system

Muscle. The 0.8 g/kg protein RDA rests on methods most researchers now consider flawed, and the right target is contested. Protein intake

Supplements. Creatine's evidence base extends well beyond gym performance, and the full picture is broader than most summaries suggest. Creatine

Biomarkers. BMD is the standard measure of skeletal strength, but what the number captures and what it misses shapes how useful it is. Bone mineral density

Every claim in these guides links to its source. The full standard is on our about page.