“Diets don’t work.” You have probably heard this claim many times, and for most people, statistics say that it is true. The question is why diets fail? Is it because you are badly thought out? Or do we only understand how you can follow you? Food scientists at William and Mary University, VA, USA, speculate that low carbohydrate and low-fat diets fail because many of us simply don’t know what is in our food.
Dr. Zach Conrad and his colleagues presented their results at the beginning of this year in an article in the Journal of the Academy of Nutrition and Nutrition. The research team, including scientists and registered nutritionists from William and Mary, Ohio State University, and the OAK Ridge Institute, examined whether people’s food diaries reflected the diet that they are supposed to follow.
Understanding the dynamics that fail the diets is of essential importance for winning the battle for the binge. In view of the metabolic disorders, it was never more important to find out why it is so difficult to stick to a plan. Overestimated nutritionist how good we are in decoding food labels? Could our tendency to give us the advantage of doubt if we report that our eating habits cause more trouble than we think?
Conrad and his team believe that it is a way. What people say they eat everything, from national nutrition guidelines to their doctor’s nutritional advice. If this information is not correct, this can lead to poor treatment recommendations, incorrect research and widespread public confusion about what works and what does not work when it comes to weight loss and healthy diet.
Forgetful or confused?
What exactly does Conrad and Co. believe that people don’t know what they eat? It all depends on how we ask the question. If your doctor asks if you stick to your diet, say yes, of course, and as far as you know, you are! The team examined whether people are so good at telling themselves, as the researchers expect from weight loss.
The researchers analyzed data from 30.219 Adults from the age of 20 who have participated in the National survey on health and nutritional examination (Nhanes) Between 2007 and 2018, Nhanes collected health and nutrition data from a nationally representative sample of Americans through two 24-hour food recallA personal and a second by phone a few days later.
The participants were asked first: “Do you currently have a diet, either for weight or for another health reason?” If they said yes, they were asked to select a certain diet from a list that contained low -carbohydrate, low -fat/low cholesterol, diabetics, low sugar, gluten -free, high protein and more.
Her answers were then compared to what they actually ate, based on their 24-hour food protocols. The researchers defined A Carbohydrate diet get Less than 26% of the total energy of carbohydratesand a low -fat diet as consuming Less than 30% of the total energy of fat. Both definitions are based on the National Lipid Association guidelines.
Low diet low
Let us settle down.
- We usually define Carbohydrate diet get Less than 26% of their daily calories from carbohydrates. It works out on a diet of 2,000 calories 130 grams of carbohydrates per dayAbout the amount in two bagels and a banana. This type of nutrition is designed in such a way that it moves your body away from the use of glucose as the main energy source and to burn fat, which sometimes even leads to a ketosis state (even though this is still strictly limited). Many popular weight loss plans such as keto or atkins fall into this category.
- The definition of A low -fat dieton the other hand consumed Less than 30% of their total daily calories from fat. That’s about 67 grams of fat per day If you eat 2,000 calories. In the 1990s and early 2000s, this approach was widely recommended for heart health and weight control and focuses on the limitation of fatty foods such as oils, butter, cheese and fatty meat cuts and at the same time promotes more fruit, vegetables and whole grain products.
These specifications are based on guidelines from the National Lipid Association’s Nutrition and Lifestyle Task ForceThe several studies checked in order to determine meaningful benchmarks for the “low” recording.
Are we asking too much?
These diets are based on quantitative measures for carbohydrate and fat content. However, is it realistic that we follow you? Despite their clinical definitions, many people do not count grams of carbohydrates or fat when eating, which often rely on general impressions or a trademark for diet. For example, someone could assume that a turkey sandwich is “carbohydrate” for wholemeal bread because it seems healthy, although it could exceed the daily carbohydrate limit for a real carbohydrate plan.
Despite the low rate of success that most people have at the fortress to these regimes, these nutritional patterns are very popular. In the The 2023 food and health survey of the International Food Information CouncilPresent over 50% of American adults said they had followed a special diet last year. Low carbohydrate and fat-low diets were the third and fourth and fourth, only behind calorie-limited and diabetic-friendly diets. These are millions of us who try to adhere to a nutrition label that, as the study shows, we may not fully understand.
And it’s not necessarily your fault. The terms “low in fat” and “low carbohydrates” are used so often in marketing and pop culture that they have lost part of their clinical importance. Without clearly defined boundaries and without education about how to eat what you eat, it is easy to do your diet too misconception. To do this, add the influence of influencers, apps and fashion diets and you have a recipe for confusion.
Force also checked studies in which low -fat diet was defined as <30% energy from fat. In this study, this limit is used to define low -fat diets.
Who sticks to the plan?
Here the numbers are interesting.
- Two hundred and ninety People in the survey stated that it was a low -carbohydrate diet. As researchers analyzed their actual admission, Only 12 (That’s just 4.1%) Consumed less than 26% of your calories from carbohydrates.
- On the other hand, 704 People said they followed a low -fat diet. Below, 162 (or 23%) eaten under the fat threshold.
This shows a clear gap between himself registered And actually Behave. It also shows that the participants understand and pursue a low -fat diet than a low -carbohydrate low -carbohydrate.
Interestingly some people who not Say, you were still fulfilled the criteria. This indicates either a random compliance or a misunderstanding of the nutritional names.
Of the first 57,414 Nhanes participants, only 30,219 were included in the final analysis. The researchers excluded the rest due to the lack of nutritional data, pregnancy or unreliable callback reporting.
If the diets do not work
This is not the first time that the diet has been marked. Previous studies using techniques such as double -marked water (A gold standard to pursue energy intake) show that people consistently examine what you eatoften without realizing it. Factors such as shame, confusion about portion sizes and poor nutritional skills contribute to this.
In some studies on weight loss, the participants reported their calorie intake by over 250 to 450 kcal per day by the end of the first year. And more than half of those who claim to follow a diet that was discontinued by the 6-month brand.
Why do diets fail
If we eat what we eat, it is not just more difficult to lose weight. It can distort national nutrition data and make nutritional advice less effective. Health service providers can rely on incorrect assumptions. The most important thing for us as individuals is we are frustrated if our so -called perfect diet does not work.
But it’s not about guilt. Most people, this data show, simply do not have the tools to precisely assess their food. Education, support and reliable tracking materials can make a difference here.
Diets do not always fail because of a lack of willpower. Sometimes we just don’t eat the diet we have think We are.
References: Kowalski C, Dustin D., Ilayan A. et al. Do people consume the diets they say? Self-reported against estimated compliance with low-carbohydrates and low-fat diets: national health and nutritional examination survey, 2007–2018. Journal of the Academy of Nutrition and Nutrition. 2025; 125 (2): 239–246. https://doi.org/10.1016/J.jand.2024.07.006