How to navigate the GLP-1 era.

Researchers now describe four "phenotypes" of obesity — hungry brain, hungry gut, emotional hunger, and slow burn — and early evidence suggests they help explain why the same GLP-1 produces dramatically different results in different people. One newly described "hungry gut" subtype lost nearly twice as much weight on tirzepatide. Here's what the phenotypes are, what the studies actually show, and what to know before paying for a phenotype test.

TDEE and BMR calculators give a useful starting estimate, but they get less reliable for people with obesity — and less reliable again after large weight loss, because of prediction-equation limits and metabolic adaptation. Here's why the number drifts, and how to correct it against what your body is actually doing.

Loose skin is fat-free tissue that body-composition scanners have no separate box for — so after large weight loss it can nudge your DXA "lean mass" up and your body-fat % down, and it complicates BIA and Seca readings too. Here's how each method (DXA, BIA/Seca, MRI) handles loose skin, how to rate them for a body carrying a lot of it, and how to read your results anyway.

The American Diabetes Association's Standards of Care is the reference most US clinicians follow, and it now puts GLP-1 medications at the center of treating diabetes with obesity. Here's what the guideline actually recommends — GLP-1s as the preferred obesity medication in type 2 diabetes, realistic weight-loss targets, the "highest dose isn't always the goal" point on dosing — plus the headline 2026 change: for the first time, the ADA cautiously supports GLP-1 therapy for people with type 1 diabetes and obesity, with important safety guardrails.

Ask whether a GLP-1 helps or hurts anxiety and the honest answer is: both happen, and most people stay stable. Steadier blood sugar, quieter food noise, and weight change calm some people; a minority develop new or worse anxiety, and drug-safety databases show a small reporting signal. It is not a treatment for anxiety. Here's the balanced evidence and, more usefully, what to monitor and when to get help.

ADHD and obesity travel together, so a lot of people on a GLP-1 also have ADHD — and many take a stimulant. There are no trials of GLP-1s as an ADHD treatment, and it shouldn't be used as one. But if you have both, three practical things matter: stacking two appetite suppressants safely, the real ADHD–eating overlap, and the adherence hurdle a weekly injection poses for an ADHD brain. Here's the honest picture.