I’m an advocator for calories in and calories out paired with macro counting and exercise for weight management. But, rising research of low-carb diets are beginning to blur our understanding of energy balance. Subsequently, it created two opposing groups of believers in the matter, sparking heavy debate and scrutiny on both sides. The battle of low-carb vs energy balance continues today, and it has been so intense that even I have come to question the foundation of calories in and calories out… ehh, not entirely.
That being said, low-carb diets DO seem to have more weight loss benefits than most other diets. For those not too familiar with low-carb diets, the concept is quite simple: Consume fewer carbs. In many cases, 50 grams of carbs or fewer per day, at least for those aiming for Keto, which is only about 2 medium-sized apples.
Although it sounds like quite an undertaking, going low-carb also means you’re allowed to eat a lot more protein and fat. The mountainous carby mash potatoes go down, but protein steaks and delicious fatty butters go up. It certainly makes the carb limitation… easier to digest, pun intended. But, what else makes it better than other diets for weight loss? One thing that many people initially experience when going low-carb is an immediate drop in water weight via the reduction of the water-retaining carb our body uses known as glucose and its stored form glycogen. Obviously, this is not exactly the fat weight you’re hoping to lose, but this can be motivational for those easily swayed by the number on the scale. Not exactly my favorite measurement tool, but alas, for many it is. The lack of carbs also promotes the state of Ketosis, as many of you already know.
Being in ketosis via low-carb dieting has been associated with the suppression of the hormone ghrelin, making you feel full quicker. But… the majority of weight loss benefits might not actually be related to the lack of carbs. If anything, it comes down to fact that you’re eating more protein. Out of the three macronutrients, protein is the only one to show consistent positive effects on weight loss. And it comes down to protein’s effect on three factors: satiation, thermogenesis, and total food intake. When it comes to satiation, almost always, more protein makes study subjects feel fuller with fewer calories. A 2005 study showed that the satiating effect of protein is so strong that it was able to decrease energy intake by 441 calories per day, hypothetically equating to nearly one pound lost per week.
It’s hypothesized that this might be due to an increased sensitivity to leptin, the hormone that inhibits hunger, when consuming more protein. In terms of thermogenesis, protein is beneficial to weight loss under thermic effect of food. Thermic effect of food is generally defined as the amount of energy it takes for the body to process the food you eat. Carbs and fat tend to have a 5 to 15% thermic effect. Protein, on the other hand, has a notably higher thermic effect of 20-35%. That means for 500 calories of carbs or fat you consume, it takes roughly 25 to 75 calories to digest it. 500 calories of protein, however, will take 100 to 175 calories. Short term, not that big of a deal… but in the long run, it can add up to a significant number of calories burned, thus more weight loss.
Finally, with total food intake, it comes down to limiting the desire to eat, aka satiety. Unlike satiation, where you feel full quicker, satiety means you feel satisfied longer. The benefit of this is that it might reduce the amount of food you eat later. One study found that, subjects that had a low protein lunch consumed 811 calories during dinner. High protein group, however, consumed only 438, almost half as much! Similar to keto, protein-induced satiety is related to the hormone ghrelin, which regulates appetite. Now, as we can see, if there’s any reason to take up a low-carb diet outside of ketosis, it’s because it naturally promotes eating more protein! Of course, it’s still important to make sure not to get too much protein, as it can present a myriad of issues, just as overconsumption of fats and carbs will. But the main takeaway is that low-carb diets can work regardless of its primary function.
And it still doesn’t go against the science of calories in and out. More protein means more calories burned and fewer calories consumed. Just like how it should be. But, if it’s true that there’s other potential weight loss benefits that we’re not yet privy to when it comes to low carb diets, it only stands to become an even stronger weight loss tool. But that’s a debate for another day… For now, let me know your opinion on the matter. Share your experiences with low carb or keto diets in the comments below, or comment if you think that all of the factors I’ve mentioned still isn’t reasonable enough for using low-carb diets.