Everything you know about low-fat and low-carb diets is wrong, according to this new study
When it comes to dieting, everyone thinks they have the answer, depending on what food trend they just heard about. But a new study suggests that we all may be making the wrong assumptions when it comes to low-fat and low-carb diets: Turns out, one isn’t better than the other. A year-long study out of Stanford University monitored a group of over 600 people, half of whom followed a low-carb diet and the other half, a low-fat diet.
They weren’t given any targets or told to count calories, just to stick to certain kinds of foods and limit either fat or carbs. For example, the low-fat diet group avoided oils, fatty meats, full-fat dairy, and nuts, and the low-carb diet group avoided cereals, grains, and starchy vegetables. Both groups were told to eat more veggies and avoid processed foods.
Since they weren’t monitored closely, they were instead offered dieting classes in which they were taught how to shop and cook for themselves and not feel deprived. Dietitians also went over “emotional awareness — to avoid stress binges, for instance — and common behavioral modifications, such as setting goals, that can help with dieting,” according to Ars Technica.
What the researchers found was that people in both groups, despite their genes and other factors, lost an average of 12 pounds each, putting the kibosh on the whole low-fat or low-carb diet debate.
Basically, if you’re eating well and being conscious about it, it doesn’t really matter which diet you choose, as long as it’s healthy.
Registered dietitian and nutritionist Tamar Samuels, who is also the founder of All Great Nutrition in New York City, told HelloGiggles that she was impressed with how comprehensive the study was, though she wasn’t totally surprised by the results.
She appreciated that the researchers emphasized that the “participants’ diets should include healthy versions of low-fat and low-carb foods, and that they should follow a version of these diets that would be sustainable for them in the long term.” She also noted that studies investigating low-carb and low-fat diets always need to be taken with a grain of salt.
"One of the bigger challenges with research on low-fat vs low-carb diets is that there are often different definitions of 'low-fat' and 'low-carb' depending on the study. Based on the study results, it looks like most of the participants ended up eating a moderate carbohydrate or a moderate fat diet — meaning the results can't really be interpreted as low-carb vs. low-fat," Samuels said.
So really, you can eat more carbs and fats than you might think and still lose weight. The most important takeaway from the study isn’t really about carbs or fats, but finding a sustainable balance to the way you eat.
Lead study author Christopher Gardner told PBS that he and fellow researchers analyzed the participants’ insulin levels and genetic variations that might be linked to how their bodies process fats and carbs, but the results this time around were inconclusive. A low-fat diet may work better for you, for example, but your friend swears by low-carb. No one has to be wrong.
He still plans on digging through the data to see if there are any links to why certain diets work for certain people, but he thinks it’s all about satisfaction. For example, some people feel like they always need a little something extra if they just have a salad, which is a problem when dieting. If you’re changing your habits and aren’t sated at the end of a day, it’s just not possible to stick to a diet long-term.
“I think the next level of personalization is really thinking about which good carbs and which good fat foods are more satiating for some people than others,” Gardner said. Samuels says that since “every BODY” is different, it’s all trial and error until then. But there are some factors that can help you choose an “eating pattern” that works best.
Samuels tells HG, “Generally, I’ve found that people who have insulin resistance do better on a lower-carb diet (but again this doesn’t mean you have to go full ketogenic — there is some flexibility on what amount of carbs works best for you). On the other hand, if your blood sugar tends to run low, I find that adding in some non-refined sources of carbs throughout the day can help with weight loss.”
If you’re really active and do a lot of cardio, Samuels says trying a lower-fat and moderate-carb diet helps with athletic performance, unless you give up carbs and start to feel sluggish or depressed. Then that’s probably not the best thing for you to try. Your age, hormones, sleep schedule, and stress are all also factors that can affect your diet.
Are you confused yet? Us too.
Samuels explains, "A great place to start is by simply monitoring how you feel when making any changes in your diet."
So note your physical state, like your energy level and how your digestive system feels, the mental affects, like if you’re fixated on food or anxious, and also your behavior, like if the diet works with your work schedule and lifestyle. Then you can tweak from there.
Basically, she recommends being your own researcher. Samuels adds, “You know more about your body than anyone else!” So as long as you feel good about what you’re eating, don’t stress about which diet trend you’re following. They work differently for everyone.