proteins (we're thinking whole protein sources such as steak) makes digestion a bit more of a task than say, breaking down a piece of bread. While this can certainly increase the amount of calories burned from digestion (protein is the most thermogenic of the macros), what this really means is that it takes time to digest. During this time, it's likely that your brain is receiving signals from the gut that you still have food available for digestion, which means you stay full (1, 2).
Additionally, the cells in your stomach that secrete the hunger hormone, known as ghrelin, are actually sensitive to stretch. When the cells are stretched, such as after a meal, ghrelin secretion ceases and you feel satisfied. Since large doses of protein can keep these cells stretched for a while, it's likely that you'll feel satisfied for a longer period of time (3).
And really, that's one of the best things you can ask for when dieting. You're increasing protein, keeping calories fairly low, and you don't feel hungry while you're doing it. That sounds like a winning combination to me.
Lastly, as I touched on in a recent research review, consuming protein might even help influence how your brain responds to traditionally "less-healthy" foods, making it less likely that you'll diverge from you diet plan due to temptation. Pretty amazing stuff.
Protein Is Muscle Sparing
Second, you have to consider protein balance. Much like energy balance, this idea stems from the notion that we are constantly building and breaking down proteins. At first that sounds bad, but really, it's a natural process that needs to occur. From there, it's thought that only when protein build up SUPRASSES that of protein breakdown that you'll build muscle. Essentially, you need a net positive protein balance in order to build muscle.
When you're losing weight and restricting calories, your focus then shifts to attempting to maintain a normal balance of protein build up and breakdown. Unfortunately, when people lose weight, this scale often tilts towards muscle breakdown.
It's theorized that if protein intake is high, the high amount of amino acids in the blood as a result, will help to encourage the body to hold onto lean muscle mass, placing emphasis on weight loss from body fat. Truth be told, this is a major reason that high protein intakes are suggested, and really, that makes sense. For the most part, why would you want your weight loss to come from muscle? (4)
Protein Is Low Calorie But Nutrient Dense
The third reason that increasing protein is recommended is largely because most proteins have a low energy density. Unless you're talking about a fatty cut of meat like ribeye or short ribs, protein typically has a large volume, yet relatively low calories.
For example, a whey protein shake provides upwards of 20 grams of high quality protein, yet only a 100 or so calories. For 200 calories, sirloin steak provides around 22 grams of protein. Chicken breast, the food of bodybuilders for decades provides upwards of 30 grams of protein in just a 4 oz. Portion.
This notion is one of the main reasons that increasing vegetables when dieting is suggested. Sure they provide micronutrients and fiber, but their high volume to low calorie ratio is really the reason that vegetables and protein help so much.
Runner Up: Protein Calories Act Differently
Keep in mind that this idea is theoretical. Protein seems to act differently in the body that the other macros. When you ingest dietary fat, it 100% can be transported to and stored into body fat. In fact, the process is quite easy for the body to do, since storing them doesn't require conversion. Carbs also have the ability to switch to fat. It's a process termed De Novo Lipogenesis, where glucose (Carbs) are transported to fat cells, stored and then converted to fat. But again, this only happens if you consume carbs in great excess of what your body requires (if you work in an office all day, your carb requirements are low, which is why many people wind up fat when their food is entirely carb based).
The body, interestingly enough does have a pathway for converting proteins to fat, only it just doesn't get used much. Why? I really don't know. I would wager that it's probably too energy costly to occur. Plus, the only time that protein might be converted to fat would likely be a time that energy intake is low. Low energy intake + a process that requires energy to actually work does not exactly make a ton of sense.
Chances are, the only way that protein could contribute to fat accumulation would be if significant excess protein was first being converted to glucose (via gluconeogenesis) and then stored and converted to triglyceride. Overall though, this doesn't even seem to happen. In fact, recent research indicates that even when people consume upwards of 4.4g / kg / day of protein, they don't gain body fat, EVEN WHEN CALORIES ARE INCREASED. These people were consuming upwards of 300 grams of protein per day AND STILL DIDN'T GAIN WEIGHT (5).
This is one of the biggest reasons why " a calorie is not just a calorie. " Clearly, protein acts differently in the body than do carbs and fat.
Overall though, the positive benefits of protein intake and the lack of evidence that higher protein intake will lead to weight gain make a fairly compelling argument for increasing protein intake, especially when you're restricting total calories.
Protein Is Satiating.
By and large, protein is the most satiating of the 3 macronutrients. The structure of protein makes digestion more difficult, which results in slowed digestion. As a result, it's likely that you'll feel fuller for longer, which can reduce binging while ensuring you remain consistent.
Protein Is Muscle Sparing
By keeping protein intake high, while restricting calories, it's more likely that weight you lose will come from fat tissue, rather than your lean muscle mass. Remember that keeping protein synthesis high is the best way to reduce the impact of protein breakdown.
Protein Is Low Calorie But Nutrient Dense
Protein is unique in that it provides a high amount of beneficial protein but total calories are often low. This is a similar concept to vegetables since you can eat a large amount of it while continuing to keep calorie intake under control. It's a winning combination for weight loss.
Protein May Act Differently In The Body
Theoretically speaking, it's unlikely that protein consumed will be converted to body fat. This makes protein a very attractive choice when combined with its other benefits if your goal is manage weight or even reduce it.
The Foods You Eat Still Matter
Based on every piece of legitimate information I've read, weight loss or gain comes down to energy balance. If you want to lose weight, you'll need to burn more calories than you ingest and if you want to gain weight, you need to consume more energy than you expend. It's an extremely simple explanation of a very complex topic, but for the most part it makes sense. The body requires energy to function. If you restrict the energy you consume, it forces the body to use stored energy (fat and muscle) to compensate.
The issue with this idea on the food side of the equation is that the foods you eat obviously have a caloric value, which helps to fulfill the energy requirements that your body has. For instance, if your body requires 1800 calories per day to function you could eat 1800 calories of pure carbohydrate and expect to neither gain, nor lose much weight (apart from water, since carbs help retain water).
Now, for the most part, there's not much wrong with this if we assume that energy balance is king. But in the real world, you need to consider if you're eating enough of the other macronutrients (protein & fat), enough micronutrients (accomplished via food diversity), and of course the right types of foods to help you feel fuller for longer.
While in terms of what is actually required to lose weight in a vacuum, calories rule everything. But in the real world, the foods you eat, very much matter if you want to have quality weight loss (losing fat while retaining muscle) and if you want to do it without hating your life.
Calorie Dense Foods Make Weight Loss More Difficult
While calories rule, the types of foods you eat can significantly influence your success and happiness. Calorie dense foods are arguably the most apparent foods that you should at least consider limiting or specifically tracking if you do decide to consume them. The reasons for this include that calorie dense foods are exactly how they sound. They have a small volume, but pack a large calorie punch.
Further, most of these foods are high in calories from 1 specific source; usually fat. Peanut butter is the poster child for calorie dense foods. Just two tablespoons have upwards of 150 calories and 16 grams of fat. Despite this fact, many market peanut butter to be high in protein, which blinds people from the truth.
While peanut butter does have protein, the protein found in peanut butter is incomplete, meaning it doesn't provide all of the necessary amino acids to build muscle. While this isn't a huge deal over the course of the day, it's important to know that peanut butter is far from being a great muscle builder.
Some of the most common offenders include:
The issue with eating these types of foods is that they significantly contribute to calories, but have little impact on the other factors of weight loss, such as helping you to stay full or helping you feel full in the first place. These factors should be the primary outcome that you're looking for when making your food decisions.
Keep in mind that many of these foods are often staples in diets. I'm not saying you can't eat these foods, you just need to understand that just because a food is labeled "healthy" (see: nuts) doesn't mean that it can't negatively affect your weight loss if not controlled.
Limit Or Specifically Track These Foods
Now that you understand why I recommend limiting these types of foods, you should consider how you'll incorporate them into your routine. I mean, to say you'll never eat pizza again is ludicris, so mapping out how you'll consume these foods is a must.
If you happen to track your food intake, being able to incorporate foods like peanut butter, ice cream or even avocados isn't too difficult, since you can just subtract the calories from your daily allowance. If you aren't tracking though, I suggest restricting how often you eat these foods or at least premeditating on when you'll consume these types of foods, such as once a week or even once per day.
Taking these steps are especially important if you're not tracking calories, since it can be quite easy to accidentally over consume. For example, the difference between 1/4 cup of walnuts and 1/2 cup of walnuts is 200 calories! For reference, 1/4 cup of walnuts is almost the exact same amount of calories as a bratwurst!
When you get to see how impactful these foods are, even foods we often associate with health, you can begin to understand how different foods can impact your health in positive and negative ways.
Both Calories And Food Matters
At the end of the day, the total amount of calories that you consume matters above all else, but you have to remember that the foods you eat are what contributes those calories. But even more, the food you eat has a significant impact on the quality of your weight loss (losing fat over muscle) and how easy it is. Focusing on foods that are satiating, while avoiding calorie-dense foods is a recipe for success, since you'll have better control over your calorie intake.
If you do decide to continue consuming these foods, I encourage you to set forth guidelines for yourself or at least consider specifically tracking these foods, to ensure that you don't have a walnut fiasco on your hands.
amount of calories each day. Some days you'll consume more and some days you'll consume fewer, but for the most part, on average you'll likely consume a similar amount of calories.
Over time, your body adapts by using this average amount of calories to function. So many calories are needed for each specific function of the body.
When you increase activity level and don't adjust your calories or if you decrease your calorie intake, the body still has a minimum requirement, based on your typical eating habits.
When you restrict calories through food, it forces your body to use stored calories from your body (body fat) in order to fuel all of these processes (at least until it adapts by increasing efficiency or reducing calorie burn - this is when you plateau!).
With regards to restricting those calories, carbohydrates are usually a great choice, since they are usually the most abundant macronutrient in people's diets, meaning carbs provide the largest pool of calories to subtract from.
This is in contrast to the other macronutrients such as protein and fat, which typically are consumed less than carbs. Not to mention, maintaining a high level of protein when attempting to lose weight is strongly advised.
In addition to protein being the most thermogenic (requires the largest amount of calories to digest), it's also the most satiating, meaning that you'll feel fuller for longer, making weight loss easy.
So, Do I Need To Remove Carbs?
The short answer is no, but it's not a bad choice. If you consume a fairly high amount of carbohydrates and are looking to drop a few pounds, reducing calories through your carb intake may be an easy decision for you.
Just know that you don't have to. If you already eat a small amount of carbohydrates but still wish to lose weight, you may need to reduce the calories you consume through fat and protein, instead.