Back in the late 1970s and ’80s, fat became the enemy. Health experts recommended reducing fats in the diet to lower cholesterol, and the food industry responded with fat-free cookies, reduced-fat peanut butter and nonfat cheese. But in processed foods, losing fat meant losing flavor. So, added sugar and refined carbohydrates replaced the fat in a lot of foods.
“When the health recommendations said to lower fats, rather than eating fruits, vegetables, pulses and whole grains, people veered toward a high-refined-carbohydrate, high-sugar diet. That can be a recipe for some health problems,” Samantha Cassetty, a registered dietitian based in New York City and the coauthor of “Sugar Shock,” told TODAY.
These days, we have a better understanding of the different types of fats in our diet and the roles they play. And some people turn to low-fat diets to lose weight. But do they work? And are they healthy? Let’s dig in.
What is a low-fat diet?
The U.S. dietary guidelines call for up to 35% of calories to come from fat. Low-fat diets aim for 30% or less — sometimes much less. Foods that contain 3 grams of fat per 100 calories or less are considered low-fat foods.
How does a low-fat diet work?
The theory behind low-fat dieting is that by cutting down on the fat you eat, you’re cutting down on the total amount of calories you consume. That’s because fat is high in calories.
Fat is the macronutrient that contains the most calories per gram. Fat contains 9 calories per gram, while protein and carbohydrates each contain 4 calories per gram. That means a small amount of a high-fat food can pack a lot of calories. For example, a tablespoon of olive oil contains 120 calories. Two cups of raw spinach, on the other hand, contain just 14 calories.
What does the research say about low-fat diets?
Some studies have found that diets low in fat can be effective for weight-loss. A BMJ meta-analysis of more than 73,000 people in 33 studies found that lowering fat may lead to small but sustained weight reduction.
However, another meta-analysis, published in The Lancet Diabetes & Endocrinology, found that low-carb diets were better for weight loss than low-fat diets. Low-fat diets only came out ahead when they were compared with usual diets, not with other weight-loss strategies.
Is a low-fat diet good for you?
That depends on what you’re eating instead of fat, and how much you’re eating. Back in the low-fat boom years, people gorged on fat-free snacks. But those snacks were loaded with calories and light on nutritional value.
When you cut out fat, or any nutrient, you need to consider what you’re replacing it with. “If you’re replacing fat with sugar and refined carbohydrates, that’s not going to put you in a healthier place,” Bonnie Taub-Dix, a registered dietitian and author of “Read It Before You Eat It: Taking You from Label to Table,” told TODAY.
“If you’re trying to watch your weight by watching the fat content of your food, that’s still a good practice, but you have to think about it relative to the other foods you’re eating,” Taub-Dix said. “Think about what you’re having in that meal and that day, and balance it nutrient-wise and value-wise.” A balanced diet is best.
What you’ll eat on a low-fat diet
If you’re trying to figure out how to lose weight, you might be thinking about trimming the fat in your diet. A low-fat diet plan is centered around carbohydrates and proteins. With a healthier low-fat diet, you’ll eat:
- A lot of vegetables, fruits and whole grains
- Some seafood, lean meat and low-fat dairy
- Little or no fatty meat, butter or oil
“Make sure you’re getting a mix of foods, so a meal isn’t just a plain bagel or a plate of pasta with sauce,” Cassetty said. She also emphasized that you should include non-starchy vegetables, protein from pulses like peas and beans as well as whole forms of soy like tofu or edamame.
- Breakfast: Whole-grain cereal or oatmeal with low-fat or fat-free milk
- Lunch: A sandwich made with whole-grain bread, lean meat, lots of veggies and mustard
- Dinner: Roasted chicken breast with lemony broccoli
- Snack: Veggies and hummus
Examples of low-fat diets
- Ornish diet, a heart-healthy diet that's low in refined carbohydrates and animal protein as well as fat
- Therapeutic Lifestyle Changes (TLC) diet, created by the National Institutes of Health’s National Cholesterol Education Program as a diet to lower cholesterol
- Macrobiotic diet, a vegetarian plan that emphasizes organic, locally grown whole foods
- Engine 2 diet, a whole-food, plant-based, low-fat eating plan
- Jenny Craig, a diet program that features prepackaged low-calorie, low-fat meals and snacks
Are low-fat diets effective long-term?
Taub-Dix says that low-fat diets can be effective over the long term, as long as you’re including some fat. “Fat in your diet is important, and healthier fats are even more important,” she said. “You can cut back on fat and still have a healthy diet.” For example, you can sauté veggies in a non-stick pan with just a little bit of oil, add a few nuts to a salad or eat fish instead of fatty meat if you’re looking for healthy foods for weight loss.
The bottom line
Talk with your doctor before starting a low-fat diet or any other diet — your doctor can recommend the best healthy diets for you and the best way to lose weight, with weight-loss meal plans based on your needs.