For people who want to pursue weight loss, whether for health reasons or to meet a certain beauty standard, restricting food intake seems to be the go-to logical, straightforward pathway to do so. The common rationalization behind this is as follows: restricting your food intake leads to less food ingested, and thereby fewer calories consumed. Fewer calories available lead to a calorie deficit in the body, and therefore, weight loss. Sounds pretty simple, right?
However, the body is much more complex than this seemingly linear pathway and is subsequently not that easily manipulated (thankfully, or else imagine what harm we could do to ourselves if our bodies simply succumbed to our efforts to control it).
Through my research and episodes of restrictive eating, I’ve learned how easily one can fall into the trap of this behavior and the unactualized promises, unsustainable results, and helplessness that it can bring about. Furthermore, as a therapist who helps treat eating disorders, I recognize that such restriction is a risk factor for developing these disorders, and a significant behavioral component of them.
Thus, for anyone who is engaged in restrictive eating, whether they are achieving the results they want or feel trapped in a cycle that no longer works, I want to straighten out some of the truths of restriction and highlight its very real effects that could lead to a potentially dysfunctional relationship with food and body image.
One phenomenon that makes our body resistant to certain manipulation is the process of homeostasis, in which the body tries to maintain stability or a status quo in its internal processes. For example, when your body is exposed to pathogens, it triggers your immune response to fight off whatever disease-causing agents are present to bring your body back to a healthy state. The same process occurs with temperature regulation. On a hot day, your brain (i.e. the hypothalamus) sends signals to your body to produce sweat in order for you to cool down, bringing your body temperature back to an appropriate level. Similarly, when someone engages in restricted eating (whether through dieting or using extreme compensatory measures to counteract food intake – excessive exercise, self-induced vomiting, etc.), your body will recognize this as starvation. Our body has become evolutionary equipped to fight against starvation, whether or not we have brought this on intentionally to lose weight, or because of food insecurity. Subsequently, your body will fight back in the same way to maintain homeostasis and ensure your survival.
Specifically, when you restrict food intake, you create a depletion of fat mass and fat-free mass and reduce the size of your fat cells (adipocytes). The body’s “defense system” is then activated to restore these depleted energy reserves (MacLean et al., 2015). As a result, your body tries hard to restore this fat loss by slowing down your metabolism and suppressing calorie burning so that you can conserve energy. Thus, your appetite increases, leading you to overeat, and as fat recovery occurs, you will gain weight.
Not only does your body try to defend against food restriction, but your brain will also intervene, doing so by measuring the amounts of leptin in your blood. Higher levels of leptin, a hormone secreted by fat cells, indicate less hunger; as you engage in restriction, you lose fat, leading to decreased leptin levels and therefore signaling to the brain that you’re hungry (Aamodt, 2016). This process contributes to the starvation response and creates food cravings that lead many to overeat or make up for the food they did not consume while restricting. In fact, your brain wants you to have the amount of body fat that will help your body function optimally, and will therefore fight back for you to reach a weight range that can sustain this (known as a “set point weight.”) (Aamodt, 2016)
Similarly to the biological fight against restricted eating, such restriction can also induce a stressful emotional response. As restriction leads to a reduction of physical reserves, limiting food intake can also bring about a feeling of emotional depletion. The Minnesota Starvation Experiment of 1944 was a famous study in which Ancel Keys and colleagues elaborated on this phenomenon. Participants of this study were 36 mentally and physically healthy men from the Civilian Public Service. The researchers put these men on a restrictive diet to study its effects: over the course of approximately one year, they reduced their diet from a usual 3,200 calories per day (three months), to semi-starvation on 1,570 calories per day (six months). This period was followed by three months of taking in 2,000 to 3,200 calories a day. Meanwhile, the men worked 15 hours and walked 22 miles per week.
During their semi-starvation period, the civilians portrayed significant psychological effects: their hunger led to a preoccupation over the thought of food, as they dreamt, fantasized, read, and talked about eating. They described depression, fatigue, irritability, apathy, reduced sex drive, and a perceived decline in mental status. Their only recovery from both their depleted physical and emotional states, was from increasing their calories, thereby illuminating that their restrictive diet had contributed to both their physical and emotional distress.
Furthermore, another explanation of such psychological effects of restriction has to do with the role of dopamine. Dopamine, a feel-good, pleasure-inducing neurotransmitter, is released during the process of eating (Bello & Hajnal, 2010). Calorie deficits and less frequent eating reduces this release, and therefore the experience of pleasure. In conclusion, being on a restrictive diet does have psychological effects that interfere with one’s emotional well-being, which reduces the sustainability of restrictive food behaviors.
What I hope you grasp from this article, if anything, is caution regarding your restrictive food habits and an understanding that your body is more powerful than you might believe. If you are purposely restricting food for whatever reason and your efforts are not working, take this as a sign that your body is trying to defend and protect itself, and try to appreciate that it is able to do so.
Bahar Moheban, M.A. is a clinical psychology doctoral candidate and registered psychological assistant in Torrance under the supervision of Dr. Nazanin Moali. She provides individual therapy and facilitates a Body Image Group for adults and adolescents with disordered eating, body dissatisfaction, and comorbid disorders. If you are struggling with bulimia nervosa or any other type of disordered eating, contact Bahar for a counseling appointment to repair your relationship with food and body image.