Hi {{first name | there}},

The right question in weight loss is not “how much?”

It is “from where?”

A pound can come from subcutaneous fat under the skin. It can come from deep visceral fat around the organs. It can come from fat in the liver, water and glycogen, or muscle you very much wanted to keep.

We all know we would rather lose fat than bone or muscle. The less obvious point is that fat loss itself is not uniform.

Subcutaneous fat, visceral fat, liver fat, and intramuscular fat do not carry the same physiology.

That is why this question matters in the GLP-1 era. In the STEP 1 extension, people regained about two-thirds of the weight they had lost within a year of stopping semaglutide. In SURMOUNT-4, people who stopped tirzepatide regained substantial weight, while people who stayed on it maintained or lost more.

That does not mean the drugs are useless. It means obesity often behaves like a chronic condition, and the tissue-level response matters: visceral fat, liver fat, waist, glucose, blood pressure, muscle, and fitness.

This letter is about how exercise, nutrition, sleep apnea care, alcohol reduction, and medication tend to affect visceral fat, liver fat, and muscle, and what I would do to lose the "right" weight as a longevity-informed physician.

A 2026 Circulation follow-up looked at follow-up from lifestyle weight-loss trials, where participants completed 18-month diet and physical-activity interventions.

At both the 5 and 10 year follow-ups, subjects regained weight.

But the MRI exams showed something interesting. Despite regaining weight, many subjects kept off abdominal fat-depot mass ("belly fat"), sustaining improvements in waist circumference, visceral fat, and abdominal subcutaneous fat.

Liver and pancreatic fat, interestingly, did not hold the same way. Those reductions were fully or excessively regained.

Regardless of other effects, each 10% loss of visceral adipose tissue was independently associated with a 28% lower risk of future type 2 diabetes during follow-up.

So if you're into weight loss for longevity, here are better metrics to track and questions to ask:

An important explanation and a review for some: not all fat is the same.

Subcutaneous fat sits under the skin, and it's not all bad. Gluteofemoral fat around the hips and thighs is a version of subcutaneous fat that can actually act like a safer long-term storage site.

In the Hoorn Study, larger hip and thigh circumference was associated with lower type 2 diabetes risk after adjustment for BMI, age, and waist circumference. In the ARIC cohort, larger hip circumference was linked with lower incident diabetes and CHD after waist and BMI were accounted for.

This doesn't mean you should necessarily aim to gain fat around the hips and thighs (and anyways, spot fat gain/reduction is not possible without surgery). However, it points to the fact that some storage depots appear less metabolically disruptive than others.

Fat infiltrating muscle is different; MRI data suggest femoral-gluteal subcutaneous and intermuscular fat are very different; intramuscular fat is quite bad for your cardiometabolic health.

Visceral fat is deeper, sitting around the organs. We'll discuss this in greater detail, but it's a "bad" kind of fat.

Ectopic fat goes where fat is not supposed to accumulate much at all: liver, pancreas, skeletal muscle, heart, and around organs.

Fat depots do not all respond to hormones and catecholamines the same way. Beta adrenergic signaling is the lipolysis gas pedal. Alpha-2 adrenergic signaling is one of the brakes. Classic human adipocyte studies found regional differences in beta and alpha-2 adrenergic receptor behavior in abdominal versus gluteal fat, and estrogen can increase alpha2A adrenergic receptors in subcutaneous fat.

That is not a “hack your receptors” invitation. It is one reason people store and lose fat in different patterns.

For today, the important idea is simpler: location is not cosmetic. Location changes physiology.

So why is visceral fat so bad? Mainly because of blood flow.

As visceral-obesity pathophysiology reviews explain, much of visceral fat sits in omental and mesenteric compartments around the gut and internal organs. These depots drain through the portal circulation toward the liver.

The liver is the first major downstream organ.

That liver-facing route gives the liver direct exposure to fatty acids, glycerol, inflammatory cytokines, and other messages from that tissue. It helps explain the clinical cluster of badness:

“Belly fat” partially encompasses visceral fat. A waist includes subcutaneous fat, visceral fat, bloating, posture, anatomy, muscle, normal variation, or even last night’s salty dinner.

The clinical question to care about: do the waist, labs, liver, blood pressure, strength, and aerobic fitness point toward risky visceral or ectopic storage?

So how do we know all this?

In the Framingham Heart Study CT cohort of 3,001 people, visceral abdominal fat, as detected on CT scans, was more strongly associated with metabolic risk factors than subcutaneous fat. It tracked with blood pressure, fasting glucose, triglycerides, HDL, diabetes, hypertension, and metabolic syndrome, plus cardiovascular disease and even cancer.

In the Dallas Heart Study, researchers followed 732 adults with obesity who did not have diabetes or cardiovascular disease at baseline. Over about seven years, 84 developed diabetes. Baseline visceral fat independently predicted incident diabetes as well as hypertension. BMI, total body fat, and abdominal subcutaneous fat were not independently associated with these bad outcomes.

Another added detail: in a later Framingham analysis, CT-measured visceral fat had a stronger association than BMI with incident diabetes and cardiovascular death in women.

This is interesting because women tend to carry more (and care a lot about) subcutaneous fat, which turns out not to be a great predictor of health, good or bad.

You cannot target fat for spot reduction, sadly.

But...you can build a plan that tends to reduce visceral and ectopic fat while protecting muscle and aerobic capacity.

Exercise is cardiometabolic treatment. The change in scale weight is only one good output.

In the CENTRAL MRI randomized trial, visceral fat decreased about 22%, intrahepatic fat about 29%, and intrapericardial fat about 11% over 18 months. Exercise independently contributed to visceral-fat reduction after accounting for weight loss.

A 2024 network meta-analysis of 84 randomized trials found that aerobic exercise, resistance training, combined training, and HIIT all reduced visceral adipose tissue in people with overweight or obesity. Vigorous aerobic exercise and HIIT ranked highest for visceral fat.

A new 2026 systematic review focused on normal-BMI and low-overweight adults, the “thin outside, fat inside” group, found that exercise reduced visceral fat in controlled studies, with aerobic training the most consistent pattern. The authors rated certainty as low because studies were small and heterogeneous, but the clinical idea is useful: a normal BMI does not prove the visceral-fat compartment is fine, and exercise can matter even when weight is not the main outcome.

My clinic version:

A 12-week supervised mixed-exercise study in women with normal-weight obesity and obesity found visceral fat and fat mass improved in both groups, while weight and BMI did not change in the normal-weight-obesity group. It was single-arm and not definitive, but the result fits the frame: the scale can look quiet while the hidden compartment changes.

There is no specific diet that selectively removes visceral fat.

The pattern that usually works is straightforward:

Mediterranean-style or lower-carbohydrate Mediterranean patterns can work well for many people. Other patterns can work too if waist, glucose, triglycerides, blood pressure, liver markers, strength, and aerobic fitness move in the right direction.

Two food/timing details are worth mentioning carefully:

I would not sell sleep or stress as visceral-fat erasers.

But sleep apnea, short sleep, circadian disruption, and alcohol can worsen glucose regulation, appetite, blood pressure, liver fat, and adherence. If someone is doing “everything right” and still has worsening waist, glucose, BP, or liver markers, I want these in the workup.

CPAP is important for the right patient, but CPAP alone is not a visceral-fat drug. Treat apnea because oxygen, blood pressure, sleep quality, arrhythmia risk, and cognition matter. Do not expect the machine to do the job of nutrition, training, and medical care.

Alcohol is more direct. A 2026 Oxford Biobank DXA study found higher alcohol intake was associated with greater visceral fat mass after adjustment for total fat mass and other confounders. Observational, yes. Clinically unsurprising. Alcohol can worsen appetite, sleep, triglycerides, liver fat, and next-day training. When it is part of the pattern, reducing it is often high yield.

This is where GLP-1s and related medications belong in the conversation.

For the right patient, I still recommend these medications even though weight often comes back when treatment stops. A chronic medication that stops helping after you stop taking it is not automatically a failed medication. Blood pressure medications behave that way too.

The question is whether the benefit while on treatment justifies the cost, side effects, access friction, and long-term plan.

GLP-1 receptor agonists and GLP-1/GIP agonists are easy to caricature as appetite drugs. That is too simple. In appropriate patients, they can reduce body weight, fat mass, waist circumference, liver fat, and in some imaging studies visceral or abdominal fat.

Examples:

The last week of incretin news points in the same direction. CagriSema improved HbA1c and reduced body weight when added to basal insulin in type 2 diabetes. Retatrutide produced large HbA1c and body-weight reductions in a phase 3 type 2 diabetes trial. Elecoglipron added another oral small-molecule GLP-1 result in obesity. And apitegromab plus tirzepatide preserved more lean mass than tirzepatide alone in a small phase 2 study.

None of that means everyone should be on medication. It means obesity medicine is moving past “how many pounds came off?” toward better questions:

That is the clinical question.

If you want the practical version, I would not start with a body MRI unless there is a reason. I would start with the pattern.

What I would not track: daily waist fluctuations, one-off smart-scale visceral-fat estimates, or any metric that makes someone less likely to eat protein, lift weights, sleep, or continue the plan.

Adipose tissue deserves more clinical attention because it sits at the intersection of energy storage, hormones, inflammation, liver metabolism, appetite, muscle, and future disease risk.

That does not mean fat is bad. It means fat is biologically specific.

For prevention, “is fat bad?” is too crude.

The better question is where energy is being stored, whether that depot is changing the rest of the body, and whether the plan can last.

Do not turn visceral fat into a shame metric. Use it as a clue that the scale was never the whole story.

If you want to make this useful this week:

Do not make this a daily body check. Use it to decide whether the plan is improving the right physiology.

The website guide is live here: Visceral Fat: How to Measure and Reduce Metabolic Risk.

Use it for the measurement hierarchy and practical tracking notes.

Hillary

The better long-form companion here is the Kyle Gonzalez episode. It gets at the same point from the exercise side: body composition is not just fat loss — it is training, recovery, glucose control, muscle preservation, and keeping a body usable for decades.

Your Workout Might Be Making You Older

This one is less about burning more calories and more about choosing the kind of training that improves the tissue you want to keep, not just the number on the scale.

Watch on YouTube | Subscribe to The Longevity Show

CKM guidelines: The new AHA/ACC/ADA/ASN CKM guideline and expected-benefit statement push cardiometabolic care toward absolute-benefit decisions, not labels alone.

Incretin pipeline: CagriSema, retatrutide, and elecoglipron keep the drug question focused on tissue quality, tolerability, access, and maintenance.

Lean mass: Apitegromab plus tirzepatide preserved about 1.9 kg more lean mass at 24 weeks, but strength and function matter more than DXA alone.

ApoB: A VESALIUS-CV analysis is a reminder that weight loss does not replace ApoB/LDL, blood pressure, kidney risk, and absolute-risk management.

Sleep apnea: In CAD patients with nonsleepy OSA, CPAP improved HFpEF-like features at 12 months, keeping OSA in the metabolic workup.

Delirium: Postoperative delirium tracked with long-term cognitive decline, so prevention and post-discharge follow-up deserve more attention.

Dry Eye Society of the Americas Conference, July 10-11, New York, NY. A clinician-focused dry eye and ocular surface meeting.

Science of Skin Summit, September 17-20, Austin, TX. Speaking on AI in dermatology and skin and hair as windows into biological age.

MVMNT 2026, September 22-23, Coronado / San Diego, CA. A physician-led longevity and clinical innovation summit; role and package are still being finalized.

Livelong Women's Health Summit NYC, September 25-26, New York, NY. A two-day summit on women's health, longevity, and agency. My role is still being finalized, but it is on the fall calendar.

A few reader-supported partners I use or would consider in the right clinical context:

If this leaves you with a real clinical question, not just curiosity, start on the testing page. It includes epigenetic age testing with consultation, plus organ-specific proteomic and SystemAge assessments when they fit the clinical question. More data is only useful when it sharpens the next decision.

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