Nutrition is science often clouded by opinion, dogma, and trends. Nutrients and diet patterns certainly affect health outcomes but the ideal dietary rubric for significantly better outcomes is hotly contended. Popular media amplifies confusion with sound bites and quick fixes that over-simplify highly nuanced information. An evaluation of scientific publications or recommendations from nutrition experts quickly becomes mired in conflicting conclusions. For even the most educated and discerning, the simple act of nourishing one’s body can become a perplexing task. To identify a clearer path towards health through food, it is necessary to first understand the limitations of nutrition research. The next step can be more difficult for analytical minds because it involves stepping back from the data to take inventory of our own day-to-day habits and how food makes us feel.
The study of nutrition is not a straight path from intervention to outcome. Randomized controlled trials (RCTs) evaluating the effect of dietary patterns on long-term outcomes are largely off the table due to poor adherence to diet intervention, time and cost constraints. RCTs evaluating single nutrients may be feasible such as in settings where the primary outcome is a resolution of a deficiency syndrome or change in biochemical marker. In contrast, differences in major health outcomes are unlikely to be significantly affected by the varying intake of a single nutrient. Observational data can be valuable in elucidating associations between dietary patterns and health outcomes, as well as generating hypotheses for further study. However, these data are rife with confounders such as differences in other health behaviors (sleep, physical activity, alcohol, and tobacco use), social determinants (socioeconomic status, access to care, implicit bias), genetics (including metabolic and gender differences), and environmental influences (quality of housing, neighborhoods, and exposure to physical hazards).
Furthermore, observational data often relies upon study participants’ diet recall. In a 2015 review published in Mayo Clinic Proceedings, authors conclude that memory-based dietary interviews and surveys are a source of predictive failure in nutrition epidemiology. They assert that diet recall is imprecise, subjective, prone to false recall, and equivocal in the absence of accurate measurement of other health behaviors. Archer et al evaluated survey data during a 39-year history (1971-2010) of the National Health and Nutrition Examination Survey (NHANES) and determined that self-reported energy intake for about two-thirds of respondents was not physiologically plausible. NHANES is used to assess nutritional status and its association with health promotion, disease prevention, and guide public health policy in the U.S.
Another important consideration for both researchers and consumers of health information is white hat bias (WHB); a term coined to reflect the symbolism of a hero in a white hat. WHB is biased leading to distortion of research-based information in service of what may be perceived as righteous ends. Nutrition topics are unique fodder as exampled by an undercurrent of morality in the classification of so-called “good” or “bad” foods. Cope and David identify examples of WHB in reporting specific nutrition interventions in source publications and press releases that were misleading or overstated in effect. A 2018 opinion article in JAMA echoes this idea and raises concern that researchers’ personal dietary beliefs and daily habits may influence the objective evaluation of data. They argue that transparency in “non-financial” conflicts, such as dietary preferences or advocacy work, is essential to safeguard data integrity and help identify potential bias.
When it comes to the daily task of consuming a healthy diet, it can be tempting to throw hands up in frustration and declare futility. But in a world of imperfect data, potential bias, and opinions short on evidence, there are truths and actionable steps.
The path to good health is paved with plants. Nearly all (actual) nutrition experts will agree that a diet rich in fruits, vegetables, whole grains, seeds, nuts, and legumes is an excellent foundation for a diet associated with longevity and decreased risk of chronic disease. Additional building blocks include sources of mono- and poly-unsaturated fatty acids and lean protein (from animal sources if desired, as well as plants). It is possible for all types of personal preferences, cultures, and means to contribute to dietary patterns that are variable but achieve a common goal of health promotion.
That said, you are more than what you eat. Health is the convergence of multiple factors. When considering personal behavior, food intake is one variable. Focusing on a diet to the exclusion of other behaviors falls short of enhancing “health span,” or years free of disease and disability. Adequate sleep, physical activity, stress reduction, supportive relationship building, community involvement, and cultivating a sense of purpose contribute to well-being and longevity. Seek opportunities to make small improvements among all spokes of the wheel.
Food is not just fuel. Food is celebration, indulgence, care, comfort, nostalgia, and connection. Hunger is certainly a primary reason for consuming food but eating only for sustenance denies so much of the joy and satisfaction that come from eating and sharing meals. Eating on the run is often a necessity in busy lives, but when able, take time to enjoy and prepare food. Sharing meals, whether that means eating with loved ones or volunteering with organizations that prepare and deliver food to those in need, can be a powerful way to foster communication, understanding, and purpose.
Your “ideal” weight cannot be found in a chart, table, or equation. Diet culture promotes a weight-centric and aesthetically motivated focus that sadly promotes a sense of failure when it comes to making food choices. For many, repairing the relationship with food and moving towards body acceptance is the first step towards better physical and mental health. Weight and body mass index should be evaluated within the context of other measures of metabolic health and wellness. Truly, the most appropriate weight is the one at which an individual can fully participate in activities they enjoy and consume food without feelings of guilt, shame, or regret.
Nutrition science will continue to evolve as researchers learn to ask better questions, improve methodology, and identify bias. The art of nourishing ourselves will hopefully also evolve as we learn to filter misleading information, avoid dietary tunnel vision, and identify motivations that add life to our years.
Lisa is a Medical Science Liaison with Fresenius Kabi USA, providing parenteral nutrition education and scientific support to healthcare professionals. As part of the Medical Affairs team, Lisa maintains scientific expertise in clinical applications of parenteral nutrition products, medical treatment guidelines, and research methods. Lisa is a registered dietitian and certified nutrition support clinician with a Master of Science degree in nutrition from Case Western Reserve University (Cleveland, OH).
Prior to joining Fresenius Kabi, Lisa spent 14 years in clinical practice at University Hospitals Cleveland Medical Center in Cleveland, OH. There, she managed the complex nutrition care of adult patients in the surgical intensive care unit and a level I trauma ICU. She regularly lectures on the topics of Nutrition Support and Critical Care Nutrition for graduate and undergraduate nutrition students at Case Western Reserve University School of Medicine. In recognition of her clinical expertise and role as an educator, Lisa was awarded the Outstanding Dietetic Educator Award in 2017, presented by the Academy of Nutrition and Dietetics.
Lisa is an active member of the Academy of Nutrition and Dietetics (AND) and the American Society for Parenteral & Enteral Nutrition. In the past, she has served as a national spokesperson for AND, member of the Oversight Committee for the Academy’s Practice Based Research Network, and reviewer for the Accreditation Council for Education in Nutrition and Dietetics (ACEND). Lisa is currently volunteering with Dietitians in Nutrition Support (DNS) as the Social Media Coordinator and is looking forward to serving on the DNS Executive Committee as the Professional Development Chair during the 2021-2023 term.