The short answer: muscle is local, fat loss is not
You cannot burn the fat over your abs by working your abs. Exercise strengthens the muscle you train, but the energy for that work comes from fat stores all over the body, not from the fat sitting directly on top of the working muscle.
The clearest test of this is a small randomized trial published in 2011. Researchers assigned 24 sedentary adults to either a control group or seven abdominal exercises, five days a week for six weeks, with everyone keeping their usual calorie intake. The ab group got markedly better at curl-ups, but there was no significant change in body fat percentage, abdominal fat, waist size or skinfold thickness.
So the crunches worked, just not for the job most men assign them. They built endurance. They did not shrink the belly.
Two kinds of belly fat, two different problems
Belly fat comes in two layers, and they behave differently. Subcutaneous fat sits under the skin, on top of the abdominal muscles; it is the fat you can pinch. Visceral fat sits deeper, inside the abdominal cavity around the liver and intestines, and it is the type more closely tied to insulin resistance and heart disease.
| Subcutaneous belly fat | Visceral belly fat | |
|---|---|---|
| Where it is | Under the skin, over the muscle | Inside the abdomen, around organs |
| How it feels | Soft, pinchable | Firm, rounded belly that is hard to pinch |
| Health weight | Mainly appearance | Linked to metabolic and heart risk |
| What a device can reach | A modest layer in the treated area | Not reached |
| What reduces it | Overall fat loss; devices can refine | Overall fat loss through diet, activity and sometimes medication |
Our condition pages on visceral fat in men and stubborn belly fat explain how to tell which one you are dealing with.
What devices like NEO Slim can actually change
Non-invasive contouring devices work on the outer layer. NEO Slim pairs strong, device-driven muscle contractions with heat aimed at fat in the treated area, so it acts on the same zone a crunch cannot: the pinchable fat over the muscle, plus the muscle itself.
The published evidence for this type of device is real but modest. A 2024 systematic review of electromagnetic muscle-stimulation devices, with and without added radiofrequency heat, found 15 clinical studies. For the abdomen, imaging showed a mean reduction in fat thickness of 5.5 mm, typically after four sessions over two to four weeks. No studies reported weight change, two reported marginal or no benefit, and the authors noted gaps in how some studies were reported.
One more caveat: the studies in that review tested devices from a single manufacturer’s line, not NEO Slim itself. Devices built on the same principle are reasonable to compare, but results depend on the specific device, the settings, the number of sessions and how much fat was there to begin with. Treat the published averages as a rough guide to what is realistic, not a promise.
Put plainly: a few millimeters of fat over the abs, a firmer feel to the muscle, and a refined contour in a man who is already fairly lean. That can be the difference between abs that almost show and abs that do. It will not turn a 40-inch waist into a 34. Our page on NEO Slim for the abdomen covers who is a realistic candidate.
Why visceral fat needs a metabolic approach
Visceral fat responds to whole-body change, not to anything applied to the skin. That means a sustained calorie deficit, regular activity, enough sleep and, for some men, medical treatment.
The CDC’s adult activity guidelines call for at least 150 minutes of moderate aerobic activity a week plus muscle-strengthening work on two or more days. Ab training fits inside that plan; it just cannot be the whole plan.
How much visceral fat matters is also why experts have moved beyond BMI. A 2025 Lancet Diabetes and Endocrinology commission on the definition of clinical obesity recommends confirming excess fat with a direct body-fat measurement or at least one measure such as waist circumference, waist-to-hip ratio or waist-to-height ratio, rather than BMI alone. Our body composition analysis does that kind of measurement.
For men with significant visceral fat, medical weight loss with semaglutide or tirzepatide, labs and regular check-ins may come first, when a provider finds it appropriate. The comparison of NEO Slim vs GLP-1 medicines explains how the two can be sequenced: lose the deep fat first, then refine the surface.
A sensible order of operations
If your goal is a flatter, more defined midsection, this sequence avoids wasted time and money:
- Measure. Waist circumference and body composition tell you whether the problem is mostly surface fat, deep fat or both.
- Check the basics. Labs such as fasting glucose, HbA1c and lipids show whether belly fat is already affecting your metabolism.
- Reduce overall fat. Food, aerobic activity and strength training, with medical support if your numbers call for it.
- Train the core. For strength and posture, knowing it will not trim fat on its own.
- Refine, if you want. Once you are near your goal weight, a contouring series can sharpen the area that diet and training leave soft.
Paying for body contouring
Body contouring for appearance is generally treated as cosmetic. IRS Publication 502 says procedures directed at improving appearance generally are not medical expenses, and it names liposuction as an example, so NEO Slim is usually not FSA or HSA eligible. Prices are not published; you get a quote before booking, and financing is available through CareCredit, Prosper Healthcare Lending and Afterpay.
How Ultimate Male helps you choose
At Ultimate Male, NEO Slim body sculpting and medical weight loss sit under the same roof, which makes the honest answer easier to give. Your first visit at San Gabriel or Downey looks at where your fat actually is before anyone recommends a device.
If the measurements show mostly pinchable fat over a reasonably lean frame, a NEO Slim series may fit. If they show significant visceral fat or early metabolic changes, the conversation turns to labs and a weight-loss plan first. Either way, start with the free 10-minute phone call at 626-319-5261.
