The updated U.S. food pyramid has renewed discussion around what it means to consume healthy fat. There are also lots of misconceptions about being ‘fat but fit’ or being ‘skinny fat’. Medical News Today speaks to experts to determine whether all fatty foods are harmful to health and whether certain body types or compositions are healthier.
For decades, adipose tissue (or, in other words, body fat) has been seen as merely a “storage depot” the body uses for insulation and fuel. However, with more research, it has become apparent that fat is akin to an organ, producing hormones and communicating with the brain and the immune system via signals.
Although most people worry about the fat you can pinch on the body, studies have uncovered that “hidden” fat, or visceral fat, is more detrimental to health and can cause organs to age. This type of fat surrounds organs and drives chronic disease.
And when it comes to the type of fat we consume, the “cut (all) fat” message from health professionals has been a universal reality. Especially regarding saturated fat, such as butter, full-fat dairy, or red meat, guidelines have traditionally called for a limit of up to 10% of daily calories.
Recent studies have questioned this threshold, suggesting that for people who already have a low risk of heart disease and low cholesterol levels, consuming saturated fat may not have as big an impact as previously thought.
But the replacement for one fat source is just as important as the fat itself.
Medical News Today spoke to three experts — Michelle Routhenstein, MS, RD, CDCES, CDN, preventive cardiology dietitian at EntirelyNourished, Kristin Kirkpatrick, MS, RDN, and Hector Perez, MD, bariatric surgeon at Renew Bariatrics and advisor at Bestsurgeons, to learn more about which fat sources are the most healthy, how much fat people should consume, and whether looking “skinny” translates to being healthy.
All three experts agreed that pushing for low fat foods and limiting fat consumption excessively was outdated advice.
“The push to eat as little fat as possible is outdated. Research has updated guidelines to focus more on overall eating patterns and the type of fat consumed rather than minimizing total fat at all costs,” said Routhenstein.
“Low-fat advice is both obsolete and naïve, in my opinion. So-called ‘fat-free’ foods are often laden with sugar to compensate,” Perez chimed in.
“Total fat intake is generally considered acceptable in the range of 20 to 35 percent of daily calories. Saturated fat limits depend on your cardiovascular risk, generally, they should account for less than 10% of your total calories per day.”
— Michelle Routhenstein, MS RD CDCES CDN
“[Basically, we spent 40 years stripping fat out of food and replacing it with refined starch and sugar, then acted surprised when obesity rates tripled, and type 2 diabetes skyrocketed. What makes ‘low-fat’ even more outdated is modern evidence, which shows that the type of fat matters far more than total fat intake. Healthy fats improve lipids, reduce inflammation, and stabilize appetite,” Perez explained.
“The quality of the diet should really take center stage when we consider which dietary pattern is best. In fact, a recent study published in the Journal of the American College of Cardiology comparing low-fat and low-carb diets found that diet quality mattered more than the specific macronutrient ratio,” said Kirkpatrick.
However, Kirkpatrick underscored that people with health conditions such as type 2 diabetes, fatty liver, or insulin resistance may benefit more from a moderate- to lower-carbohydrate approach, which could help improve blood sugar control.
Current research supports swapping saturated fats for polyunsaturated and monounsaturated fats, which can help decrease the levels of LDL or ‘bad’ cholesterol.
Underscoring that monounsaturated and polyunsaturated fats are beneficial for brain and heart health, Kirkpatrick gave examples of healthier alternatives for people looking to reduce their saturated fat intake.
“These healthier fats are found in foods like extra-virgin olive oil, avocados, nuts, seeds, and fatty fish such as salmon,” she said.
Meanwhile, Routhenstein reminded that eliminating saturated fat completely from one’s diet may not be feasible for most people.
“I would assess where saturated fat is coming from in your diet and intentionally swap it for an unsaturated fat source instead; swapping is more beneficial than eliminating the saturated fat altogether,” she said.
Perez pointed out that making the right switches in one’s diet was important and that people should try to avoid replacements that are heavily processed.
“If you reduce saturated fat, replace it with monounsaturated and omega-3 fats like olive oil, nuts, fatty fish, instead of refined carbohydrates. Swapping steak for sugary cereal is not a win,” he said.
Routhenstein also encouraged people to seek whole foods rather than focusing solely on fat content.
“For example, full-fat dairy (containing saturated fat) also provides protein and calcium, which can support satiety as well as bone and muscle health,” she said.
“Rather than obsessing over fat, I think it’s high time people educate themselves about nutrients that are actually good vs. bad for their bodies. I’ve seen people cut saturated fat and replace it with bagels and low fat snack bars, which just seems to me like changing the villain,” Perez added.
“Of course, and that’s why I ask my patients not to rely on just their BMI as a health indicator. I’ve seen 120-pound patients with fatty liver, insulin resistance, elevated triglycerides, and metabolic syndrome,” Perez said.
He also explained the difference between looking ‘thin’ and having healthy body fat.
“We now recognize the phenotype called ‘TOFI — Thin Outside, Fat Inside,’ where deep visceral fat accumulates despite a normal outward appearance. Just because the mirror looks OK doesn’t mean your internal biology agrees,” he said.
“Someone can appear thin but still have higher levels of visceral fat or metabolic risk factors. The number on the scale isn’t always the best indicator of overall health or long-term disease risk,” Kirkpatrick added.
This has also been referred to as “skinny fat” on social media.
Excess body fat is one of the primary drivers of metabolic syndrome, which can increase the risk of a range of conditions such as type 2 diabetes, cardiovascular disease, and high cholesterol.
“Metabolic disease is an internal storm that often precedes external weight gain, especially in people with sedentary lifestyles, poor diets high in sugar and refined starches, or genetic predisposition,” Perez explained.
“Being lean in appearance does not guarantee protection from cardiometabolic disease. This is why measuring cardiometabolic indicators such as waist circumference, blood pressure, cholesterol, glucose and insulin levels, and inflammatory markers is more informative than relying on the scale alone,” said Routhenstein.
Research has consistently shown that visceral fat, or fat that surrounds organs, is more detrimental to metabolic health.
Kirkpatrick said that where fat is stored in the body can matter for long-term health.
“Where fat is stored predicts your health far better than how much total fat you have. A lean BMI doesn’t immunize you from fat-driven pathology if that fat is centrally deposited,” Perez pointed out.
“[A] thin person with visceral belly fat is at higher metabolic risk than a heavier person with mostly subcutaneous buttock or thigh fat,” he said.
The experts also explained the differences between visceral and subcutaneous fat and the biological mechanisms at play in both.
“Visceral adipose tissue sits deep, bathes the liver and organs in pro-inflammatory cytokines, worsens insulin resistance, and drives atherogenic profiles. Subcutaneous fat is more like insulation, bulky but less biochemically toxic,” Perez said.
“Visceral fat [is] strongly linked to higher risk for chronic diseases like heart disease and diabetes. Subcutaneous fat, which sits just under the skin, does not carry the same level of metabolic risk,” said Kirkpatrick.
“For this reason, waist circumference and certain metabolic markers are often more useful for assessing health risk than body mass index or weight alone,” added Routhenstein.
