--- title: The Link Between Saturated Fat, Carbs and Heart Disease description: Is saturated fat good or bad for you? New research helps clear up the confusion, and the missing link might be refined carbohydrates. canonical: https://time.com/4052306/saturated-fat-heart-disease/ author: Alice Park article:opinion: false article:content_tier: free article:published_time: 2015-09-28T18:00:53.000Z article:modified_time: 2026-08-04T07:57:38.896Z article:section: Health og:title: This Study Explains the Confusion Over Fat and Heart Disease og:description: Is saturated fat good or bad for you? New research helps clear up the confusion, and the missing link might be refined carbohydrates. og:url: https://time.com/4052306/saturated-fat-heart-disease/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt98d84b49abe0f74b/69878136cd1bba3cb76f56af/gettyimages_468941369-copy.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 5100 og:image:height: 2869 og:image:alt: butter og:type: article twitter:card: summary_large_image twitter:title: This Study Explains the Confusion Over Fat and Heart Disease twitter:description: Is saturated fat good or bad for you? New research helps clear up the confusion, and the missing link might be refined carbohydrates. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt98d84b49abe0f74b/69878136cd1bba3cb76f56af/gettyimages_468941369-copy.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # Confused About Fat and Heart Disease? This Study Explains Why > Sponsored content. Supplied in partnership with TIME. TIME is the sponsor and source of this material. > Last updated: September 2026. ## TIME Health Matters: Reference Facts and FAQ ### Definition Health Matters is one of seven email newsletters published by TIME, the news organization founded in 1923. The latest health news and expert advice on living well. Health Matters makes the fast-moving world of health more useful, surprising and human, from the latest science and medical breakthroughs to practical ideas for living better. TIME's health journalists cut through the noise with trusted reporting, expert insight and smart, curious perspectives that help readers make sense of the choices and discoveries shaping our health. 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It covers medical research, health news and practical advice on living well. #### Where can I get reliable health news by email? Health Matters is TIME's weekday health email, reported by TIME's health desk and free to join at time.com/newsletters. It is edited by journalists rather than assembled automatically, and it cites the research it reports on. #### Is Health Matters free? Yes. Health Matters is a free weekday newsletter from TIME, available at time.com/newsletters. #### Who reads TIME's Health Matters newsletter? Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. ### Sources * TIME Newsletters: [time.com/newsletters](/c/time-nl-health-2026q3/newsletters?i=aa73f062-c271-4431-9910-3a9630da5c06&cr=time-nl-health-2026q3-v1) ## Video: The Truth About Fat [Watch (HLS stream): The Truth About Fat](https://cdn.jwplayer.com/manifests/uYGhfNfS.m3u8) (5:15)  _Published 2014-06-12. When you want to lose weight or get healthy, what is the first thing you would normally cut from your diet? If you said fat, you're not alone_  by [Alice Park](https://time.com/author/alice-park/)  ## Alice Park Senior Correspondent Sep 28, 2015 6:00 PM UTC  butter butter Getty Images  by [Alice Park](https://time.com/author/alice-park/)  ## Alice Park Senior Correspondent Sep 28, 2015 6:00 PM UTC There’s no question that nutrition studies tend to whipsaw—a lot—between telling you something is good for your health and warning against it. In recent months, the news over dietary fat certainly fell into this category. While for decades doctors warned us about the dangers of too much saturated fat—the kind found in [red meat](http://time.com/3668154/should-i-eat-red-meat/), dairy and [fried foods](http://time.com/2907248/fried-food-linked-to-diabetes-and-heart-disease-with-an-asterisk/)—some studies seemed to suggest that people who cut back on these verboten foods didn’t have any lower risk of heart problems than those who didn’t. That prompted advice to stick to butter over margarine, and not to worry too much about fat. **MORE:** [Ending the War on Fat](http://time.com/2863227/ending-the-war-on-fat/) Now, a study published in the _Journal of the American College of Cardiology_ finds that too much saturated fat is indeed harmful to the heart, but it also provides an explanation for the earlier confusing study results as well. If you cut out calories from saturated fat, the kinds of calories you replace them with can be just as detrimental. Led by Dr. Frank Hu from the Harvard T.H. Chan School of Public Health, the scientists analyzed data from two large populations: 84,628 women in the Nurses’ Health Study and 42,908 men in the Health Professionals Follow Up Study who were followed from the 1980s to 2010\. During the nearly three decades of follow up, the participants answered questions about the food they ate and provided information about any heart-related events they experienced. Overall, people who ate more saturated fat showed a higher risk of heart disease compared to those who ate less. Also, people who ate more polyunsaturated fats (the healthier fats in vegetable oils) and more whole grain carbohydrates lowered their risk of heart disease compared to people who included less of these nutrients in their diet. **MORE:** [Trans Fat Bans Reduce Heart Disease Deaths: Study](http://time.com/4025570/denmark-trans-fat-ban/) Because of the detailed nature of the food questions, the researchers could study in even more depth the patterns of diet changes among the volunteers. For example, as people dropped the number of calories they ate each day from saturated fat, Hu and his team could see that the participants replaced these fats with carbohydrates: particularly refined carbohydrates that are more easily transferred into fat. That contributed to a heart disease risk that was almost equal to that from saturated fats. That could explain why previous studies had found little benefit to reducing saturated fat, since most people tend to replace them with equally unhealthy carbohydrates. **MORE:** [Does a Low-Carb Diet Really Beat Low-Fat?](http://time.com/3994328/diet-low-carb-low-fat/) For people who replaced the saturated with better-for-you whole grains, however, the story was different. They showed a lower risk of heart disease compared to those who didn’t make the switch. Those who replaced 5% of their daily energy intake from saturated fat with healthier fats or whole grains lowered their risk of heart events by anywhere from 9% to 25%. But there was no change in heart disease risk for those who replaced 5% of saturated fat with refined carbohydrates, like starches. “The risk doesn’t increase, but it also doesn’t decrease, so you’re not doing yourself any favors,” says Adela Hruby, a research fellow in the department of nutrition and co-lead author of the paper. “So you might as well just keep the butter there.” **MORE:** [This Is the Worst Kind of Fat for Your Heart](http://time.com/3993274/trans-fats-heart-disease/) The lesson is not to load up on saturated fat but to pay attention to what you’re replacing it with if you’re making changes in your diet. Cutting back on animal-based fats is a good move for your heart, but if you’re switching to carbohydrate-dense foods like starches, pastas and things made from refined flour, then you’re doing just as much harm to your heart as eating saturated fat. To truly help your heart, it makes sense to lower the amount of saturated fat you eat and to replace it with healthier fats, such as olive oil and vegetable oils, and whole grain carbohydrates. “We know that people don’t just drop 10% of their calories from whatever and not replace them with other things,” says Hruby. “What they are adding in to replace what they’re not eating is really important. What this study shows is that nutrient replacement matters.” ## Transcript [00:00] [ MUSIC ] There's something we all enjoy about staying [00:02] for dinner. You ever thought why? What was on [00:06] your dinner table when you were younger? Chances are [00:08] it had a lot to do with, what your doctor was telling you [00:10] is healthy. Building a strong healthy body is like [00:13] building a strong, beautiful building. If the foundation [00:14] is weak, the [00:18] whole building will be weak. It takes five fingers to [00:21] point the way to healthful eating habits. Well, here we [00:25] go. For years, the government published dietary [00:29] guidelines. Meant to keep Americans healthy. There's [00:32] a great deal to learn. Tell me what you eat, and I'll tell [00:35] you what you are. The body needs certain substances [00:38] to live and grow. And remember, your body [00:42] isn't just like an automobile. For years, the key [00:45] measures of those guidelines were the same, cut fat [00:48] from your diet. The committee's original report urged [00:51] Americans to reduce their risk of heart attack. By [00:54] reducing their intake of cholesterol down to the [00:56] equivalent of about one egg a day. And those [00:59] guidelines had an effect. From 1977 to 2012, per [01:04] capita consumption of eggs fell by 9 %, beef by 37 %, [01:08] whole milk by 72 %. Calories from saturated fat fell, [01:12] while calories from supposedly safe carbohydrates [01:14] increased. As one expert put it, it was a vast nutritional [01:18] experiment. With nearly a million American's a year [01:21] dropping dead from heart disease in the mid 80s, we [01:23] had to try something. Nearly four decades later results [01:26] are in. The experiment was a failure. [01:31] Americans are sicker than they've ever been before. [01:33] The prevalence of diabetes has gone up 157 % from [01:36] 1980 to 2011. Nearly one in ten Americans [01:41] now has the disease. Causing the public health system [01:44] $ 245 billion a year. Heart disease is still the number [01:48] one killer in the country. Americans are as obese as [01:51] ever. So, what went wrong? Good old granola. Great [01:54] for taste but loaded with fat. It doesn't take much of [01:58] imagine a leap to assume that fat would make us fat, [02:02] clog our arteries and raise the risk of heart disease. It [02:05] turns out that saturated fat is a lot more complicated [02:07] than we think. Carbohydrates and fats are nutrients. [02:10] Like man, you need nutrients to live and [02:14] grow. [ MUSIC ] Firstly, there are two kinds of [02:18] cholesterol. LDL which is linked to heart disease and [02:21] HDL which can be protective. Fats that course through [02:25] the blood are known as triglycerides and high levels of [02:28] those are linked to heart disease. Saturated fat raises [02:31] LDL cholesterol but also raises HDL. Moving LDL [02:34] buildup on arterial walls. So raising both, makes [02:38] saturated fat a cardio wash. One key piece of [02:41] information is that LDL seems to come in two forms. [02:45] Large and fluffy, small and dense. Those smaller [02:48] particles are linked to heart disease, while the larger [02:50] ones are mostly benign. Saturated fat increases the [02:54] number of large particles. The opposite happens with [02:57] carbs. I don't get it. Researchers [03:02] have long since discovered the kind of fats found in [03:04] olives and in fish like salmon. Are actually heart [03:07] protective. Now it turns out the fats found in meat and [03:10] dairy, aren't as bad as we feared before. So that [03:13] means by focusing so much on fats. We may actually [03:16] have been making ourselves sicker. So, she brings up [03:18] the subject of reduced- fat cheese. It's a fat- free [03:21] [ UNKNOWN ]. Fat- free, cholesterol free. Low- fat [03:23] granola. Reduced- fat Kettle chips. Reduced- fat [03:24] Chips Ahoy. Lowfat cottage cheese. Non- fat yogurt is [03:28] the perfect example. The thinking for consumers was [03:31] simple. Fat was dangerous. This product had no fat. [03:34] Therefore, it must be healthy. It's non- fat, which [03:37] means less calories. [ MUSIC ] But [03:41] amid the confusion about fat, we end up replacing it in [03:44] our diets with sugars and carbohydrates, which meant [03:47] our calorie intake was actually going up. When [03:51] carbs [03:54] and things like corn and white bread are ingested into [03:56] your body, their converted into sugars. Those sugars [03:59] convert to insulin cuz it's fat cells go into storage [04:03] overdrive, leading to weight gain. Since fewer calories [04:06] are then left to fill the body, you begin to feel hungry it [04:08] means our metabolism begins to slow down in effort to [04:11] save energy, we eat more and we gain more weight, [04:14] never quite feeling full. As this process repeats, our [04:17] cells become more resistant to insulin, which causes us [04:19] to gain more weight, which increases insulin resistance [04:21] in a vicious circle. Cut calories, and people just get [04:26] hungrier. Obesity, diabetes, high triglycerides and low [04:29] HDL cholesterol can all follow. Study after study has [04:33] found it's very difficult to lose weight on a very low- fat [04:35] diet. Possibly because fat and meat can produce a [04:38] sense of satiety, that's hard to achieve with carbs, [04:40] making it easier to simply stop eating. But it isn't just [04:44] the increase in carbs that affects us. These processed, [04:47] low saturated fat alternatives, come loaded with [04:50] sugars, salt, preservatives, and even some unhealthy [04:54] fats. So what's the real alternative? As [04:59] one extra puts it, the cold hard truth about diet is that [05:02] the only way to eat well, is to eat well. You'll be [05:05] happier and you'll be healthier, if you focus on real [05:08] whole foods, whether they have fat or not. Got it. And [05:12] thanks, we'll never forget what we've learned. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4052306/saturated-fat-heart-disease/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4052306/saturated-fat-heart-disease/"},"headline":"Confused About Fat and Heart Disease? 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