Because the question in the title has long been controversial, some of you may believe one way, others the opposite, but would really like to know the truth, not just keep one’s opinion. A powerful new study that measures fat loss more accurately gives evidence that it is better to lower fat than carbs. This new study, published in Cell Metabolism kept experimental subjects in a metabolic ward, where body fat loss could be accurately measured after reducing carbs or fat in the diet. Many health professionals are hoping that this thorough study will end the debate about the effectiveness of low carb or low fat diets. If the ultimate goal is to decrease body fat and not just see the scale temporarily move down, then this is important information.

One of the interesting facts about this research is that the persons in the study were residing in a metabolic chamber. (Essentially, a metabolic chamber is like a larger version of a lab rat’s box. It is a climate-controlled room hooked up to a series of recording and analyzing devices.) The low carbohydrate diet led to a loss of 53 grams of body fat daily; and the low fat diet, equal in calories to the low carb diet, led to a loss of 89 grams daily.

So if all their work was correct, it’s pretty clear what was going on. Unlike most observational studies, it’s not just saying which group lost more weight, a group on a low fat diet or a group on a low carbohydrate diet. As we discussed last week, water fluctuations can really muck up the results of observational research. So this new research has given a big heads up to the scientific community. Many people are writing about it and saying things like; ‘we finally know that low fat works better than low carbs.’ But is there more to it than meets the eye at first glance? Of course. How to benefit from this information is not simple.

There are a couple of interesting facts that the researchers shared with Health Day reporter Alan Mozes.

• First, their study suggests that total calories are the primary driver of fat loss; not the type of calories consumed. Kevin D. Hall, the lead researcher said; “People are not able to control or monitor their food intake as carefully as was done in our study.” That is so true! Many people don’t realize that foods usually have all three macronutrients in them; protein, carbohydrate and fat. People often call foods protein foods; like whole milk which in actuality is: 48% of calories from fat; 31% of calories from carbohydrate; and 21% of the calories from protein. Or even a food like whole grain bread, considered by many, as only a carb is 71% carbohydrate; 16% protein and 13% fat. And are desserts fats or carbs? Frosted chocolate layer cake is just almost 50 – 50; half carbs and half fat. Chocolate chip cookies also are just about a 50-50 tie in carbs and fat. Apple pie about 60% carbs and 40% fat; but the fact still is that it is not clearly one macronutrient or the other. Most foods are not strictly fats, protein or carbs. Even the fatty avocado (delicious and nourishing) is not just fat; 76% fat; 4% protein and 20% carbohydrate.
• Some people believe that a low carb diet reduces the effect of insulin; but the reduced fat diet in the study, led to loss of body fat at a greater rate than the reduced carb diet; even though the calories were equal and there was no observable effect on insulin production. So we can only hope that the days of carbs being a pariah are over. I’m not naïve enough to believe that those days will end immediately, but this may be one of the beginning steps. The big hope is that this study helps to debunk the myth that all carbs are bad for weight control. If you eat fewer calories than your body needs for maintenance, even if those calories are proportionately high in carbohydrates, you will lose body fat, according to this study. My hope is that people will stop being afraid of carbs, the way they used to be afraid of fat (1980s and ‘90s). I don’t mind if they’re cautious with sugar (eg candy, soda, cake, etc) and its empty calories; but there seems to be lots of fear of fruit, milk, whole grains, and even some are afraid of the carbs in vegetables – missing all the nutrients that are provided by these foods.

So what do we learn? The story is the same as always. Eating is not just about calories; it is the way we nourish our bodies and give them all the nutrients to keep us healthy. Getting quality calories from nutrient-rich quality foods is the best way to stay healthy while losing weight. If you consume fewer calories than your body needs, you have to get the calories to keep your body functioning from somewhere, so the body uses its fat stores.

You can read a selection from many blogs on these subjects here at Dr. Grandma’s, to give yourself ideas of changes you can make to reduce your calories. For example, if you switch from whole milk (see percentages above) to nonfat milk, there is 59% carbs; and 41% protein and, of course, essentially no fat. This is one of those changes to an eating style that is easy to maintain. For a cup of milk, the calories are reduced by 65 calories for each 8-ounce cup. That change also reduces fat by 8 grams for each cup; and that’s mostly saturated fat. So this is a nice example of how to make sustainable changes and benefit from the study cited above.

Reducing portion size of calorie dense foods and/or, decreasing frequency of those foods is another way to reduce total calories. When questioned about how to reduce calories, I almost always start by advising an increased consumption of vegetables. Vegetables are foods usually low in calories, with a wealth of nutrients. Increasing vegetable consumption, allows a person to be filled with fewer calories and feel satisfied more easily.

It makes sense to be careful with fat consumption, because the same weight of fat has more than twice as many calories as protein or carbohydrate. It does not mean that we should not consume fat, because fat is necessary for satiety and fat-soluble vitamin absorption and other bodily needs. So let’s not swing back to fat phobia. OK?

If we ever grasped the concept that changing our eating style, which is the most important part of maintaining a healthy body and weight, then we would not be overly concerned if a low fat or low carb diet was slightly more effective. The fact is that learning to eat and exercise is the most important part of weight management. In can be done in a way that will help us maintain a lower weight – achieved in a way that we as an individual can maintain. We need to learn what works for us – what we can do, to stay healthy or become healthier.