Skip to main content

Verified by Psychology Today

Health

3 Ways Your Mind Could Be Manipulating Your Metabolic Health

Why metabolic health is more about the mind than the gut.

Key points

  • Mental factors may be as important to our metabolic health as diet and exercise.
  • Research shows that memory is both a cause and consequence of weight gain and metabolic health problems.
  • The primary benefit of food logging, reading food labels, and mindful eating practices may be that they improve memory and awareness.

While opinion wars rage on social media over nutrition, research is quietly revealing that what is going on in your mind may be more important than what you are putting into your mouth or stomach. If you are tired of the debates over the virtues of plant-based versus ketogenic diets or the vices of sugars and saturated fats, then take heart: macronutrients play a relatively minor role in the metabolic health outcomes of your nutrition program (1). Meanwhile, factors such as your mindset and food beliefs have surprisingly large effects not only on the types and amounts of food you eat, but even on how your body physically responds to the meals you consume.

Here is why your food plate may be less important than your mental state when it comes to nutrition and how you can translate this information into practical applications.

1. Memory and metabolic function

Consider some of the following highly counterintuitive research findings:

  1. Patients with types of dementia or brain damage that leave them incapable of forming new memories (i.e., they immediately forget what they just did or who they just met; think of Drew Barrymore's character in 50 First Dates), will consume full-course meals back-to-back-to-back without becoming full. Unable to remember that they just ate, it is as if the satiety signals from their stomach are ignored by the brain (2).
  2. Laboratory studies among cognitively healthy college students show that they eat fewer afternoon snacks when prompted to recall what they had for lunch. In contrast, when the same student population is distracted during lunch, asking them later to recall their noontime meal no longer reduces subsequent snacking. Being able to form and recall memories about our recent eating behavior appears to directly influence subsequent appetite.
  3. Neuropsychological and neuroimaging studies indicate that higher levels of body fat may impair memory function—relationships that are even observed in overweight children—and that these memory deficits may predispose further weight gain by dysregulating eating behavior (2). Interestingly, achieving significant fat loss through methods such as bariatric surgery produces lasting improvements in memory function (3). These studies suggest that poor memory may be both a cause and consequence of excess fat gain and that the effect may be reversible.

In short, anything that impairs memory function regarding what and how much we've eaten seems to remove a vital part of our brain's ability to regulate appetite and metabolic changes (see figure below). Although the brain receives "bottom-up" chemical signals from the stomach and organs about the foods we eat, "top-down" messages from the brain to the digestive organs are equally if not more powerful. When these "top-down" signals are impaired, unfortunately, the above research suggests that the stomach and other digestive organs alone may be insufficient to protect our metabolic health.

Thomas Rutledge
Source: Thomas Rutledge

2. The hidden power of eating awareness

Real-time awareness of what we're eating and drinking may be just as important as our ability to remember. Many people, for example, have experienced situations where they consumed large amounts of food while watching television or were otherwise eating while distracted. During periods of extreme stress or strong emotions, some people similarly report disinhibited eating patterns, resulting in altered food preferences and excess calorie consumption. And who among us has not experienced a time when we innocently consumed an entire packaged meal or beverage and were later amazed to learn how many calories the item contained after reading the label?

These effects of food awareness—knowing that you're eating and what the food contains—are powerful and well-supported by research (e.g., 4). When we eat, our brain processes visual and other sensory cues to help regulate our appetite (your eyes really are bigger than your stomach!). In circumstances, therefore, where these sensory cues are diminished by distractions, emotions, or environmental factors, we can consume much more food and drink than under normal conditions. In one of the most famous demonstrations of the food awareness effect, people ostensibly participating in a study to taste-test soup recipes consumed almost 75% more soup when their soup bowls were secretly being refilled (5). Despite this excess consumption, they reported being no more full than people eating from regular soup bowls.

3. You are what you think you're eating

The third piece of the metabolic health mindset concerns your attitudes and beliefs about what you're eating. In two recent studies on this theme, Dr. Crum and her colleagues showed that:

  • Labeling an otherwise identical milkshake as either "indulgent" or "sensible" caused people receiving the former shake to experience a more rapid decline in ghrelin (ghrelin is a primary hunger hormone, with lower levels corresponding with satiety; thus, when people thought the shake was "indulgent" rather than "sensible," their stomach hormonally registered it as more filling; 6). Remarkably, the participants' beliefs about the calories and contents of the shake had a greater metabolic influence than the actual calories and contents.
  • Labeling vegetables as either plain (e.g., "carrots"), health-promoting (e.g., "low-calorie carrots"), or taste-promoting (e.g., "Cajun-style carrots") altered both how likely people were to purchase the vegetables and how much of the vegetable they consumed (7). Notably, other than the different labels, the actual vegetables were the same. It was their perceptions about the food created by the labels rather than the actual taste or ingredients that drove consumption. This study also showed—surprising to many—that the health-promoting labels performed the worst. At least in America (similar studies in European countries frequently do not show this effect), health qualities of food are often perceived negatively and may even make people less likely to purchase them.

Many other studies indicate similar patterns. If you recall the Dr. Seuss book Green Eggs and Ham, food psychology research suggests the effect is real. What we perceive and believe about the food we eat—through "top-down" chemical signals delivered from the brain to the digestive system—alters how the food tastes and how our body responds.

4. Translating the metabolic mindset to action

The influences of memory and mindset on metabolic function are not only widespread and substantial in modern American society, but they are also potentially actionable. Without intentional strategies on our part, unfortunately, the cultural ubiquity of multitasking, mental stress, restaurant patronage, and ultra-processed foods make us far more likely to be victimized by these factors than to benefit. However—as shown in figure 2 below—it is possible to translate our awareness of these same factors into practical behaviors to improve our health and well-being.

Thomas Rutledge
Source: Thomas Rutledge

Although many people may have received advice from health professionals to keep food records, eat more mindfully, and consume food at a slower pace, they likely never considered that these behaviors help in part by improving our memory about what and how much we've eaten. In the same way that a student performs better by paying attention and taking notes during class, the rest of us can benefit in terms of metabolic health performance by applying the same strategies.

While we intuitively recognize that eating while distracted, upset, or excessively from restaurants and processed food packages aren't good for us, this research reveals what they all have in common: each tricks us into eating more by limiting our brain's ability to detect what we're eating. Developing practices to read food labels, preparing your own food when possible, and eating only when you have the calm and focus to pay attention to the food can counter these interfering factors.

Finally, it still amazes many people to learn (or recall) that spinach was rated by U.S. children in the 1930s as one of their favorite foods—right after turkey and ice cream—because of its association with the popular Popeye character to whom spinach granted strength and courage. Even if spinach isn't your thing, however, the practical lesson is about adopting empowering (e.g., taste appeal, desirable virtues or benefits from consuming, etc.) attitudes about nutritious food. As this research shows, the benefits are equally large among adults.

References

1. Sacks FM, Bray GA, Carey VJ, Smith SR, Ryan DH, Anton SD, McManus K, Champagne CM, Bishop LM, Laranjo N, Leboff MS, Rood JC, de Jonge L, Greenway FL, Loria CM, Obarzanek E, Williamson DA. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009 Feb 26;360(9):859-73. doi: 10.1056/NEJMoa0804748.0-59. doi: 10.1007/s13679-018-0296-9.

2. Higgs S, Spetter MS. Cognitive Control of Eating: the Role of Memory in Appetite and Weight Gain. Curr Obes Rep. 2018 Mar;7(1):50-59. doi: 10.1007/s13679-018-0296-9.

3. Alosco ML, Spitznagel MB, Strain G, Devlin M, Cohen R, Paul R, Crosby RD, Mitchell JE, Gunstad J. Improved memory function two years after bariatric surgery. Obesity (Silver Spring). 2014 Jan;22(1):32-8. doi: 10.1002/oby.20494.

4. Robinson E, Aveyard P, Daley A, Jolly K, Lewis A, Lycett D, Higgs S. Eating attentively: a systematic review and meta-analysis of the effect of food intake memory and awareness on eating. Am J Clin Nutr. 2013 Apr;97(4):728-42. doi: 10.3945/ajcn.112.045245.

5. Wansink B, Painter JE, North J. Bottomless bowls: why visual cues of portion size may influence intake. Obes Res. 2005 Jan;13(1):93-100. doi: 10.1038/oby.2005.12.

6. Crum AJ, Corbin WR, Brownell KD, Salovey P. Mind over milkshakes: mindsets, not just nutrients, determine ghrelin response. Health Psychol. 2011 Jul;30(4):424-9; discussion 430-1. doi: 10.1037/a0023467.

7. Turnwald BP, Bertoldo JD, Perry MA, Policastro P, Timmons M, Bosso C, Connors P, Valgenti RT, Pine L, Challamel G, Gardner CD, Crum AJ. Increasing Vegetable Intake by Emphasizing Tasty and Enjoyable Attributes: A Randomized Controlled Multisite Intervention for Taste-Focused Labeling. Psychol Sci. 2019 Nov;30(11):1603-1615. doi: 10.1177/0956797619872191.

advertisement
More from Thomas Rutledge Ph.D.
More from Psychology Today