Diet & Nutrition

The Skinny on the Low-Fat Diet

Once considered the key to healthy weight loss, the low-fat diet has fallen out of favor in the wake of the low-carb/Keto craze. But when done the right way, it can still be a healthy and effective eating plan.

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Once the country’s go-to eating plan, the low-fat diet now seems so … ’80s. Fats and oils are our newest celebrity nutrients, with starring roles in Keto, Paleo, low-carb, and even vegan eating. It makes sense: Fat concentrates flavor and enhances aroma, and fat-rich foods have a uniquely satisfying texture and mouth feel. Fat also helps you stay full longer, which can actually help you eat less.

But while it’s far from trendy, limiting dietary fat may protect your health—especially if you’re a woman. Here’s what you need to know.

How It Started

The demonizing of fat began in 1977 with the release of Dietary Goals for the United States. The report urged Americans to reduce dietary fat as a way to slow skyrocketing rates of obesity, heart disease, diabetes, and cancer. By 1980, a scientific consensus emerged around the benefits of a low-fat diet, and by the end of the decade, the Surgeon General, Department of Health and Human Services, USDA, and World Health Organization were all promoting low-fat eating.

Predictably, food manufacturers began churning out low-fat versions of everything from mayonnaise to cookies. “Heart-healthy” reduced-fat foods flooded grocery store shelves, and hungry consumers gobbled them up.

How It Stopped

The problem: fat is tasty—so to make their goods more palatable, manufacturers added extra sugar, salt, flour, and artificial ingredients to low- and no-fat packaged products. The result: a plethora of refined, processed foods that were lower in fat, but higher in sugar, sodium, and calories. Even worse, saturated fats were replaced with trans fats—now associated with a significant increase in the risk of heart attack and stroke.

When reduced-fat diets failed to move the needle on heart disease, diabetes, and obesity, health experts suggested the profusion of lower-fat processed foods might ironically promote the fattening of America. Restricted-fat diets fell into disfavor, and the pendulum swung far in the other direction with  fat-centric eating regimens such as Keto and Paleo.

How It’s Going

You need good fats to stay healthy. But lowering your intake of fats and oils may also have health benefits. Here are 8 things you may not know about the low-fat diet:

  1. Low-fat doesn’t mean no fat. Your body needs fat for hormone production, absorption of fat-soluble vitamins (A, D, E, and K), and other biological functions. Current guidelines recommend 20–35 percent of total daily calories come from fat, and a low-fat diet hovers at the low end of that range. That means you’ll still eat fat—in moderation, and the right kinds.
  2. The low-fat diet is fussy about fats. On a proper low-fat diet, fewer than 10 percent of daily calories come from saturated and/or animal fats. Essential fatty acids from fish and monounsaturated and polyunsaturated fats (omega-3 and omega-6 fats), avocado, olives, nuts, and seeds are the main focus.
  3. It’s naturally high in nutrients. What do blueberries, spinach, broccoli, lentils, carrots, and quinoa have in common? Besides being super-low in fat, they’re loaded with antioxidants and other nutrients that protect against disease. Research consistently links a nutrient-rich diet rich in fruits, vegetables, legumes, and whole grains with lower rates of cancer, cardiovascular disease, respiratory disease, and all-cause mortality.
  4. You’ll get plenty of fiber. One of the biggest problems with fat-centric eating plans: they tend to be low in fiber. Increasing dietary fiber protects against heart disease, diabetes, metabolic syndrome, and other conditions. And some research suggests that a high intake of fiber can cut the risk of heart disease by as much as 40 percent.
  5. You may lose weight. Fats weigh in at 9 calories per gram, more than twice the 4 calories per gram found in proteins and carbs. So the low-fat diet automatically tends to be lower in calories, and studies suggest that people who cut daily calories by eating less fat lose weight. The weight-loss benefits are greatest if you’re following a clean, whole-foods regimen. If your diet is made up of reduced-fat packaged or processed foods, laced with sugars and refined carbs, you may end up consuming more calories.
  6. It may prevent heart disease. The interplay between dietary fat and heart disease is complex and controversial. There are dozens of studies that show restricting dietary fat can improve cholesterol profiles, reduce blood pressure, and lower levels of C-reactive protein, a marker for inflammation. And ultra-low-fat variations (like the Ornish Diet) that limit fat to 10 percent of daily calories may not only prevent, but even reverse, cardiovascular disease.
  7. It may have extra benefits if you’re a woman. A low-fat diet may be especially protective for women, slashing the risk of heart disease and breast cancer deaths. One large-scale study of 50,000 women found a low-fat diet emphasizing fruits, vegetables, and whole grains lowered coronary heart disease by as much as 30 percent and reduced death from breast cancer by up to 35 percent. Women who followed the low-fat eating protocol were also 13–25 percent less likely to develop diabetes.
  8. A low-fat diet can be a lifelong eating plan. Because it doesn’t eliminate entire food groups or restrict foods rich in vital nutrients like fiber and antioxidants, a well-designed low-fat diet can be a lifelong regimen. In fact, some of the best-researched diets—such as the Mediterranean Diet and the DASH Diet—curb fat intake. If you’re going low-fat for the long haul, follow a few simple rules for the healthiest outcome:
  • Focus on a clean, whole-foods diet based on vegetables, fruits, legumes, whole grains, and lean protein.
  • Use packaged, processed foods as occasional treats, and be sure they’re free from added sugars, refined carbs, and trans fats.
  • Stick to polyunsaturated fats (walnuts, flaxseeds, cold-water fish, chia seeds, pine nuts, sunflower seeds, pumpkin seeds) and monounsaturated fats (avocados, nuts, seeds, olives, and olive oil).
  • Don’t go too low. Unless you’re following an ultra-low-fat diet for a serious health condition (with the supervision of a medical professional), eliminating or severely restricting fats can impact your health.

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(Photo: Pornchai Mittongtare)

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