ARE WE REALLY WHAT WE EAT?2
Are We Really What We Eat?: The Importance of Macronutrient Composition in Diet
Rebecca Collins
Dixie State College
ARE WE REALLY WHAT WE EAT?2
Abstract
Many people are concerned with losing weight or improving their health, and with good reason. Obesity is predicted to become the leading cause of death and can increase a person’s risk for many kinds of fatal health complications. When trying to lose weight, many wonder what sort of diet is the most successful for weight loss or which is the healthiest diet for the body. Low-carbohydrate diets are popular, but cannot be recommended because the weight loss that results is rarely maintained. High-protein diets have shown greater success for long-term weight loss, due to the thermogenic effect of this macronutrient, which results in a higher metabolism and prolonged feelings of fullness. Fats have been shown to have positive effects on the diet, and which fats are consumed can seriously impact weight loss and maintenance. However, though the food we choose to eat has a significant impact on our health, weight loss is not dependent on what we eat, but rather how much we eat—however, what we eat has a direct effect on how much we eat. The importance of physical activity and a regular sleeping schedule are also important factors when attempting weight loss. Individuals will gather that “dieting” is not an efficient approach to weight loss, and understand the importance of implementing subtle behavioral changes over time to maximize weight loss efforts and adopt a long-lasting healthy lifestyle.
Keywords: macronutrients, weight loss, weight maintenance, physical health, nutrition, diet, lifestyle, obesity
Are We Really What We Eat?
You are what you eat—this is classic proverb common to our society has become quite the cliché throughout the years. But could it really be the truth? Many people concerned with weight loss wonder about this question; does it really matter what you eat when losing weight, or does it only matter how much? Many people know to lose weight they must restrict the number of calories they are consuming, but if a person eats a certain caloric number of apples and bread or the caloric number of chicken breasts and spinach, will the weight loss reflect what was eaten, even if the caloric number between diets was consistent? There seems to be a lot of hullabaloo about this topic; someone always has a shocking new answer, advocating some diet sure to drop pounds fast. One day a low-carb and high-protein regime is the sure way to go, while the next someone is advocating a diet focused on average-protein and high-fat. Does the composition of our diet significantly affect our weight loss? The answer that I have found is that yes it does; but at the same time, no it does not.
In my experience, every diet has an equal and opposite binge; if I am good and eat a specifically controlled sort of diet for a short amount of time, I tend to be moderately successful for just long enough to realize how much I miss my old eating habits, which then results in a relapse in which I overcompensate for missing those foods, finding myself back at square one quicker than ever. This tends to be the way of most dieters, and this system of resolving to follow fad diets so often followed by quick lash backs can’t be helpful to our diet—in fact, I believe it can even be harmful and detrimental to a person’s actual weight loss goals. The problem with a “diet” is that a diet will end, and some six-month made-over eating regime can’t miraculously change the eating habits that a person has established throughout a lifetime. Working towards healthy lifestyle is a much more productive goal than adopting the latest trendy diets.
Why Diet Matters
While the macronutrient ratio of our diet (the three macronutrients being carbohydrates, protein, and fats) may have been shown not to significantly affect weight loss in a fixed-calorie setting, ad libitum studies have proven that what we eat has a direct influence on how satisfied we are with our diet, which affects how much we eat. For this reason, weight loss is incredibly difficult to achieve without altering the composition of the macronutrients in our diet. Schusdziarra et al. (2011) points out in one study that behavioral interventions have been proven to be one of the most if not the very most important factors for successful weight loss. Since different macronutrient ratios of our diet affect our behavior and thus our total energy (calorie) intake and satiety or fullness, one can see that while the macronutrient composition may not directly influence weight loss, modification of the ratio in some way is of the utmost importance in achieving weight loss.
While this information may seem to be important only to those interested in losing weight, the macronutrient composition of a person’s diet also affects not only his or her internal health, but also his or her ability to maintain a healthy weight. This is an issue that everyone needs to be aware of, due to the rapidly rising issue of worldwide obesity. Obesity is defined as having a BMI (body mass index) of 30 or over, and obesity increases the chances of developing all sorts of life-threatening complications such as cardiovascular disease, hypertension, and even certain cancers (MacDonald, 2005). In fact, McLaughlin et al. (2006) even mentions that obesity is projected to be the leading cause of death in the United States if something does not change. Even if we are not at risk due to obesity, chances are that someone we know and love is at in danger of developing weight-related health problems. Thus, it is extremely important to be aware of the effect the foods we eat may be having on our bodies and increase efforts to manage weight on a long-term scale.
Even more alarmingly, even our genes are being affected by our diet and lifestyle. Bray (2008) mentions this in his review of Taubes’ book Good Calories, Bad Calories, writing that “some factor of diet and/or lifestyle must be driving weight upward, because human biology and our underlying genetic code cannot change in such a short time.” (p. 253). Though the urgency of weight loss has been a prevalent issue for several centuries, over the past few decades our lifestyle has changed drastically to include less day-to-day activity and a higher consumption of highly processed foods. MacDonald (2005) submits that we no longer are in tune with our bodies and don’t know what they need, and we often turn to the cheap convenience of junk food rater than choosing fresh fruits and vegetables or lean proteins and whole grains. This simply is not having a positive effect on our health and, evidently, even our genome.
Katz (2010) even goes so far as to point out that on the cellular level, we really are what we eat, since the composition of our blood, hormones, bone marrow, and even cell membranes are all determined by the nutritional content of our food. Thinking of it this way, our bodies literally are made out of the food that we eat, and therefore our bodies will only be as clean and healthy as the food that we put into them (Katz, 2010).
The Big Three Building Blocks
Carbohydrates
There are three macronutrients that make up every diet, as previously mentioned: carbohydrates, fats, and proteins. When most people try to diet, they typically will turn to the popular approach of committing to a low-carbohydrate diet with high-protein; many studies have explored this type of diet, however, and while success has been achieved in the short-term, follow ups have often shown that low-carbohydrate diets are not successful in sustaining weight loss. In a study done by van Baak and Astrup (2009) exploring the effect of sugars on weight loss, the carbohydrate content of a diet was actually found to be relatively benign, with little evidence found for dietary sugar having directly negative effects on body weight—instead, van Baak and Astrup (2009) submit that “the ratio of other macronutrients in the diet may be more important.” (p. 10).
In spite of this, carbohydrates can be ignored. In van Baak and Astrup’s (2009) same study, different sugars were in fact shown to have different effects on the body. While we all know that drinking sugar- and high fructose corn syrup-sweetened beverages has a detrimental effect on our health, we may be underestimating the extent to which we are sabotaging ourselves when consuming sugar in liquid form. The habit of drinking one or more soft drink per day was shown to result in higher likeliness of obesity as well as increased waist circumference when compared to a control group who consumed the same amount of sugar in a solid form, by way of jelly beans (van Baak & Astrup, 2009). In both cases, the increased sugar intake also tended to replace regular intake of fat and protein as well, which proves another way that sugar—regardless of whether it is liquid or solid—is negatively affecting our diet.
The replacement of other macronutrients with sugar carbohydrates could also be a result of the way sugar tends to spur consumption of more sugar. For example, think of how much easier it is to be satisfied after eating a small amount of raw almonds as opposed to how easy it is to achieve satiety eating a small amount of honey-roasted almonds; that sugary coating often drives a person to eat more (Katz, 2010). Processed foods are often full of these kinds of refined sugars, which result in flavoring that can overly stimulate the hypothalamus, or the appetite center of our body. This effect results in unintentional consumption of greater amounts of low-fiber carbohydrates (sugars rather than whole grains, for instance), which leads to eating food with a high ratio of calories to nutrients and consequently an overall higher caloric intake (Katz, 2010).
Therefore, while it is futile to sustain a low-carbohydrate diet (Sacks et al., 2009) and low-carbohydrate diets cannot be recommended (van Baak & Astrup, 2009), it is important to be wary of how many carbohydrates we are consuming and the quality of those carbohydrates. It doesn’t take too much common sense to realize that eating carbohydrates in the form of an apple (natural sugars) is a wiser choice than eating a candy bar (refined sugars). Natural sugars also tend to be present in foods with a higher content of fiber and water, which fills up the stomach more and increases feelings of satiety, resulting in feelings of greater satisfaction and a lower energy intake overall.
Proteins
Protein is another highly-advocated macronutrient in the weight loss circuit, with high protein regimes showing a little higher success rate than low-carbohydrate diets in the long run, with sustainable long-term weight loss (van Baak & Astrup, 2009). In a study conducted by Due, Toubro, Skov, and Astrup (2004) in which the effects of medium-protein and high-protein diets were compared in relation with weight loss, the high-protein group was shown to not only lose 3.5 kg more weight, but also had a greater reduction in waist circumference. These findings suggest that a high intake of protein might influence the distribution of fat and result in a reduction of abdominal fat. Due et al. (2004) hypothesized that this indicates a correlation between consumption of protein and reduction of cortisol, a hormone caused by stress that causes excess abdominal fat, but that is a question for later studies.
Another reason that increased protein has been proven to be so successful in weight loss is the thermogenic effect of this particular macronutrient. The thermogenic effect is known as the way that foods can increase the amount of heat the body creates in digesting them, resulting in a heightened metabolic rate for a short amount of time. Protein has the highest thermogenic effect of all the macronutrients—27% of the calories of pure protein a person consumes will be used in digesting this macronutrient (Due et al., 2004). This means that not only will metabolism be quickened by consumption of protein, but because protein is difficult to digest, it will stay in the stomach longer resulting in greater feelings of satiety and fullness. All of these things contribute to an overall lower energy intake, which in turn leads to more successful weight loss.
Eating more protein has also been associated with eating less of the other two macronutrients: fats and carbohydrates. Due to the aforementioned thermogenic effect of protein, eating high protein generally replaces calories otherwise spent on less filling foods, resulting in eating less. One study reports that intentionally replacing fats with proteins resulted in more pronounced weight loss among participants (McLaughlin et al., 2006) and another review of studies found that the influence of higher protein intake on lower intakes of other macronutrients resulted in significantly higher, better-maintained weight loss in the long-term (van Baak & Astrup, 2009). Thus, increasing the protein intake in one’s diet can result in greater long-term weight loss and weight management, because protein increases feelings of fullness which leads to decreased total caloric intake.
Fats
The last macronutrient, fat, has a universally bad reputation. However, this macronutrient is an important part of our diet. Just as we should avoid choosing refined sugars over whole grains when consuming carbohydrates, fats are not created equal. Polyunsaturated and monounsaturated fats can actually result in a subtle reduction of abdominal fat (Sacks et al., 2009), while inversely, trans fats and excessive amounts of saturated fat have been known to dramatically increase the amount of visceral (abdominal) fat in the body. Schusdziarra et al. (2011) points out that fats have a higher energy density, meaning they have a lower satiating capacity than other macronutrients. In van Baak and Astrup’s (2009) review of sugars and body weight, the fat content of a diet was also shown to be “the most important contributor to passive over-consumption” (p. 9), suggesting that eating fatty foods tends to spur the appetite to crave fatty foods and result in the consumption of more high-calorie foods and consequently greater calories overall, much like sugary foods. Therefore, while healthy fats have been advocated as important element of a healthy diet and have their time and place, the fat content of a diet still ought to be monitored and caution must be taken to ensure that the majority of fats being consumed are the healthier unsaturated fats.