Glossary

24h Recall

The 24-hour recall is a structured interview. It collects a list of all foods and drinks consumed during the previous day or the preceding 24 hours. Although computer-based 24-hour-recalls are available, they are typically face-to-face interviews. The interviewer must be trained to remain neutral and not ask leading questions. Read more

Added sugar

The term added sugars refers to sugars and syrups added to foods and drinks during processing and preparation (World Cancer Research Fund, 2015). Read more

Adequate Intake

The Adequate Intake (AI) is the average observed or experimentally determined approximation or estimate of nutrient intake of a population group (or groups) of apparently healthy people that is assumed to be adequate. Adequate intake is the value estimated when a Population Reference Intake (PRI) cannot be established because an Average Requirement (AR) cannot be determined (EFSA, 2017). Read more

Amyloid-𝛽

A peptide derived from the amyloid precursor protein, commonly found in the central nervous system. Abnormal levels of amyloid-𝛽 can aggregate between neurons, disrupting their function. Amyloid-𝛽 plaques are among the earliest pathological signs of Alzheimer’s disease.

Android Obesity (Central Obesity)

More fat accumulation around the torso, with accompanying visceral fat. Less subcutaneous fat and limb fat. Colloquially described as 'apple-shaped'.

APOE4

A risk gene associated with an increased likelihood of developing Alzheimer’s disease. The presence of more APOE4 copies elevates the risk and may lead to an earlier onset of the disease. However, it's important to note that having APOE4 does not guarantee the development of Alzheimer’s disease.

Arteriolosclerosis

Thickening of the blood vessel walls. Often occurs in the blood vessels of the brain independent of plaque buildup.

Arteriosclerosis

Hardening of the arteries caused by atherosclerosis.

Association

Association is a very general relationship. One variable provides information about another. But it doesn't prove causation. Read more

Atherosclerosis

The process of hardening and thickening of artery walls by the accumulation of fatty plaque.

Autoimmune Condition

A malfunction of the immune system whereby an inflammatory response mistakes the body’s own tissues for a foreign invader and attacks them. Read more

Average Requirement (AR)

The Average Requirement (AR) is the level of (nutrient) intake estimated to satisfy the physiological requirement or metabolic demand, as defined by the specified criterion for adequacy of that nutrient, for half of the people in a population group, given a normal distribution of requirement (EFSA, 2017). Read more

Baroreceptor

Baroreceptors are rapid pressure receptors within vessels that send signals to the brain which modifies cardiac output and vascular tone. They are located in the aortic arch and carotid sinus. They are sensitive to pressure and stretching. Read more

Bias

Bias is a systematic error that distorts the true association between different variables. Systematic errors are consistent and reproducible. It blurs the actual value of what’s being measured. There are many types of biases. Read more

Big Food

Big Food refers to multinational food and beverage companies with vast and concentrated market power. Read more

Body Mass Index (BMI)

Population measure of fatness. BMI = weight (kg) ÷ height (m2).

Bottom-up approach

A bottom-up approach equals a reductionist approach. It studies the effects of isolated elements in food. See also the reductionist approach. Read more

Calorie density

The number of calories in a given weight of food. Low calorie density foods have fewer calories per kilogram than high calorie density foods.

Cardiac output (CO)

The amount of blood that is pumped through the body in 1 minute. Cardiac output = Stroke volume x Heart rate (CO = SV x HR).

Causation

Causation means that a change in one variable causes a change in another variable. There’s a cause-effect relationship between the two variables. In other words, the variables change together due to a direct or indirect causal link. Read more

Circadian rhythm

Circadian rhythms are 24-hour cycles that exist in all types of organisms. The term circadian comes from the Latin circa, meaning “around”, and diem, meaning “day.” Almost every cell contains one of these 24-hour clocks called circadian clocks. These clocks optimize biological functions. Every function in the body has a specific time because the body can’t do all it needs to at once. They interact with the timing of light and food. Read more  

Comorbidities

Comorbidity occurs when a person has more than one disease or condition at the same time. Conditions described as comorbidities are often chronic or long-term conditions. Other names to describe comorbid conditions are coexisting or co-occurring conditions and sometimes “multimorbidity” or “multiple chronic conditions.” Comorbidities are often non-communicable diseases.

Confirmation bias

Confirmation bias is an error in thinking. Our brains tend to pick information that supports our pre-existing beliefs.  As a result, we tend to ignore any information that contradicts those beliefs. This leads to faster decision-making. Read more

Confounders

A confounding variable influences a potential cause-effect relationship. It’s an unmeasured factor. It is independently associated with the exposure and outcome. Left unchecked, confounding variables can introduce many research biases. It causes you to misinterpret your results. Read more

Contrast in exposure

It’s the comparison between the defined high vs low doses and exposures. Two servings per week of red meat vs none, for example. Read more

Corporate sponsorship

It’s a form of marketing. A company could support a person or an organisation by giving them money. The sponsor gets recognition in exchange for funding the project or program. Read more

Correlation

Correlations are more specific than associations. They refer to a statistical and linear association between two random variables. For a positive correlation, the two variables increase at the same time and similarly. For a negative correlation, it’s vice versa. Read more

DALY (Disability Adjusted Life Years)

One DALY (Disability Adjusted Life Years) represents the loss of the equivalent of one year of full health. DALYs for a disease or health condition are the sum of the years of life lost due to premature mortality (YLLs) and the years lived with a disability (YLDs) due to prevalent cases of the disease or health condition in a population. Read more

DASH diet

The DASH Diet (Dietary Approach to Stop Hypertension) focuses on vegetables, fruits and whole grains. It includes fat-free or low-fat dairy products, fish, poultry, beans and nuts. The diet limits foods that are high in salt, also called sodium. It also limits added sugar and saturated fat, such as in fatty meats and full-fat dairy products (Mayo Clinic). Read more

Determinants of health

The range of personal, social, economic and environmental factors that determine the healthy life expectancy of individuals and populations. Read more

Diastole

The phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.

Dietary assessment

A dietary assessment gathers information on what a patient eats and drinks in a given period. The data is then usually converted using food databases to calculate intakes of energy, nutrients, and other dietary components. Read more

Dietary pattern

A dietary pattern represents the quantity, variety, and combination of foods and drinks. It also captures how often they are usually eaten. Read more

Dietary Reference Intakes (DRIs)

The term Dietary Reference Intakes (DRIs) are used in the US. At PAN we refer to the European Food Safety Authority (EFSA), which uses the term Dietary References Values (DRVs).

Dietary Reference Values (DRVs)

Dietary Reference Values (DRVs) are an umbrella term for a set of nutrient reference values that includes the Average Requirement (AR), the Population Reference Intake (PRI), the Adequate Intake (AI), the Reference Intake range for macronutrients (RI), and the Tolerable Upper Intake Level (UL), which indicate the amount of an individual nutrient that people need for good health depending on their age and gender (EFSA, 2017). Read more

Digestible Indispensable Amino Acid Score (DIAAS)

The Digestibile Indispensible Amino Acid Score is used to assess the quality of a protein source. DIAAS takes into account the digestibility of amino acids more accurately than the previous Protein Digestibility Corrected Amino Acid Score (PDCAAS) (FAO, 2011). Read more

Disease-modifying antirheumatic drugs (DMARD)

DMARDs are Disease-modifying antirheumatic drugs. These include anti-TNF𝛼 and immunosuppressive agents. Read more

Double-blinding

Double-blinding means that the subject and the researcher performing the experiment are blinded. They both don’t know the subject’s group assignment. Double-blinding can reduce the risk of bias. Read more

Dysbiosis

The loss of harmony and balance within the gut microbiome caused by an imbalance between beneficial and harmful bacteria.

Dyslipidaemia

Blood levels of circulating cholesterol and triglycerides above the normal range.

Ectopic fat

Fat accumulation in non-adipose tissues such as muscle and organ tissue.

Effect size

Effect size tells you how meaningful the relationship between variables is. Or it measures the difference between treatment groups. The larger the effect size, the more significant the treatment effect. A significant effect size means that a research finding has practical significance. In contrast, a small effect size indicates limited practical applications. Read more

Empowerment

In health promotion, empowerment is a process through which people gain greater control over decisions and actions affecting their health. Read more

Essential nutrients

Essential nutrients are compounds, which are required for growth, reproduction and good health. The human organism is not able to synthesize these compounds, therefore, an adequate intake of those nutrients is required from external sources, such as diet. Read more

Evidence-based practice (EBP)

Evidence-based practice (EBP) is using the best available evidence for decision-making. It’s a process used to review, analyse, and translate the latest scientific evidence. It’s about providing efficient and effective care for patients on a scientific basis. Read more

External validity

External validity is the extent to which you can apply the study results to other contexts. See also validity. Read more

Fibre

Fibre (fibre in US spelling) can be specified as complex carbohydrate polymers (3-10 polymers) and lignin, which are resistant to digestion by endogenous enzymes and thus are not absorbed in the small intestine of humans (FAO/WHO, 2009). Read more

Fibrosis

The accumulation of extracellular matrix proteins (e.g. collagen, elastin, fibrin, fibronectin, and proteoglycans) causing thickening and scarring of tissue. This can occur in organs and blood vessels.

Food balance sheet

Food balance sheets (FBS) portray a country’s food supply and use pattern over time. They are essential for measuring global food security. They are helpful for international comparison and analysis of trends over time; as they are standardized and updated. Read more

Food Frequency Questionnaire (FFQ)

Food Frequency Questionnaires (FFQs) include food items and ask about the intake frequencies. How often do you drink coffee or tea per week or month? And what’s the average serving per day? FFQs may include more questions on cooking methods or adding salt, oils, herbs, and spices. Depending on how an FFQ is designed, it can consist of 50 to 150 food items. Read more

Food record / Food diary

Food diaries can be divided into weighed and estimated diaries. Weighed food diaries are the gold standard in clinical nutrition studies. Every serving size, including any leftovers, is weighed. In an estimated food diary, yet, the serving sizes are estimated using household utensils or food photos. Read more

Food synergy

Aristotle said, “The whole is greater than the sum of its parts”. It’s the synergy’s essential meaning. Likewise, isolated nutrients are less effective in protecting us against various diseases than whole foods containing those nutrients. Foods are complex mixtures of thousands of complementing nutrients. So, the food they come from, or the food combinations, impact our health and well-being. Read more  

Free sugars

Free sugars refer both to added sugars, like sucrose or table sugar, and sugars naturally present in honey, syrups, fruit juices and fruit concentrates. Most free sugars consumed are added to foods and drinks. Free sugars do not include sugar that is naturally built into the structure of foods or to sugars naturally present in milk and milk products (World Cancer Research Fund, 2015). Read more

Glia cells

Various brain cells that provide support, nourish, and protect neurons. Common types include astrocytes, microglia, and oligodendrocytes. Read more

Glucose Homeostasis

The balanced actions of glucagon and insulin to maintain blood glucose levels within normal range.

GLUT4 Transporter

Is the most abundant glucose transporter (GLUT) isoform in skeletal muscle and adipose tissue. It is responsible for insulin stimulated glucose uptake (Chadt and Al-Hasani, 2020). Read more

Glycaemic index (GI)

The glycaemic index assigns a score to a food, based on its ability to raise blood sugar levels. Foods ranked on a scale from 0 to 100. However, using glycaemic index as indicator for carbohydrate quality has its limitations. (FAO/WHO, 2007). Read more

Glycaemic load

The glycaemic load assigns a score to a food, based on its ability to raise blood sugar levels, but takes into consideration how much glucose per serving the particular food can deliver. The glycaemic load also has its limitations when assessing carbohydrate quality (FAO/WHO, 2007). Read more

Grey matter

Brain tissue composed of neuronal cell bodies and dendrites. Grey matter is crucial for signal processing in the brain.

Gynoid Obesity

More subcutaneous and limb fat, with less visceral and torso fat. Colloquially described as 'pear-shaped'.

Hard clinical endpoints

A hard endpoint is an endpoint that is well-defined and can be measured objectively. Hard endpoints in hypertension trials include death, stroke, and myocardial infarction. Read more

HbA1c

Haemoglobin A1c is also known as glycated haemoglobin. Red blood cells have a lifespan of approximately 120 days. Thus, HbA1c reflects blood glucose levels over the preceding 3 months. Diabetes is defined as having a HbA1c ≥ 6.5% and pre-diabetes between 5.7-6.4%. Normal HbA1c is ≤ 5.6%. Read more

Health

A state of complete physical, social and mental well-being, and not merely the absence of disease or infirmity (WHO,2021).

Health Claims

A health claim is any statement on labels, advertising, or other marketing products. It states consuming given food can result in health benefits. For instance, consuming certain food can enhance learning ability. Read more

Healthy diet

According to the WHO, a healthy diet for adults includes:

• At least 400 g (i.e. five portions) of fruits and vegetables per day
• Legumes (e.g. lentils and beans), nuts and whole grains (e.g. unprocessed maize, millet, oats, wheat and brown rice)
• Less than 10%, preferably <5% of total energy intake from free sugars
• Less than 30% of total energy intake from fats, less than 1% of total energy intake from trans fats
• Less than 5 g of salt

Heart rate (HR)

The number of times the heart muscle contracts and relaxes in 1 minute. Also called the pulse.

Hyperplasia

The enlargement of an organ or tissue caused by an increasing number of cells. In the case of obesity, hyperplasia relates to an increase in the number of fat cells.

Hypertension

Blood pressure over 130 mmHg (systolic) and 80 mmHg (diastolic) in the USA. Blood pressure over 140 mmHg (systolic) and 90 mmHg (diastolic ) in Europe. Read more

Hypertrophy

Cell growth. In blood vessels, vascular hypertrophy results in the thickening of the arterial tunica media. In adipose tissue, hypertrophy results in abnormally large fat cells. Hypertrophy also occurs in skeletal and cardiac muscles.

Incidence

Incidence is a rate. It refers to the number of new cases that develop during a specified time interval, like a month or year. Cases are study participants who have developed any outcome of interest, like high blood pressure (compare with Prevalence as they are often confused). Read more

Information bias

Information bias occurs during data collection. It relates to systematic errors in how a variable is measured. For example, if a diagnostic test classifies exposed subjects as non-exposed. Read more

Internal validity

Internal validity describes how reliable and trustworthy the established cause-and-effect relationship is. See also validity. Read more

Interviewer bias

Interviewer bias is the tendency of the interviewer to get preconceived answers. They may ask leading questions systematically influence the interviewee’s response. Read more

Ketogenic diet

A ketogenic diet primarily consists of high fats, moderate proteins, and very low carbohydrates. The dietary macronutrients are divided into approximately 55% to 60% fat, 30% to 35% protein, and 5% to 10% carbohydrates. Read more

Lifestyle medicine

Lifestyle Medicine is the use of evidence-based lifestyle therapeutic intervention—including a whole-food, plant-predominant eating pattern, regular physical activity, restorative sleep, stress management, avoidance of risky substances and positive social connection—as a primary modality, delivered by clinicians trained and certified in this speciality, to prevent, treat and often reverse chronic disease. Read more

Macronutrients

Macronutrients provide energy and are required in large amounts to maintain body functions and essential processes. Macronutrients include carbohydrates, fat, protein and water (WHO). Read more

Macrophages

Macrophages are specialised cells involved in the detection, phagocytosis and destruction of bacteria and other harmful organisms. In addition, they can also present antigens to T cells and initiate inflammation by releasing molecules (known as cytokines) that activate other cells. Read more

Malnutrition

Malnutrition refers to deficiencies, excesses, or imbalances in a person’s intake of energy and/or nutrients. The term malnutrition addresses 3 broad groups of conditions:

• undernutrition, which includes wasting (low weight-for-height), stunting (low height-for-age) and underweight (low weight-for-age)
• micronutrient-related malnutrition, which includes micronutrient deficiencies (a lack of important vitamins and minerals) or micronutrient excess
• overweight, obesity and diet-related noncommunicable diseases (WHO, 2021)

Matching

Matching is a way to control for confounders at the study design stage. It’s only used in case-control studies. Each subject in the treatment group has one counterpart in the control group. The matched subjects have the same values on any potential confounder. For example, they both match in age or smoking status. Read more

Mediterranean diet

A traditional Mediterranean diet is predominantly vegetarian. It’s high in diverse whole plant foods, including fruits, vegetables, whole grains, legumes, nuts, and seeds. Read more

Metabolic healthy obesity

Obesity lacking metabolic abnormalities or evidence of cardiovascular or lifestyle disease progression.

Micronutrients

Micronutrients are consumed in small quantities but are essential to body processes. Micronutrients include vitamins (water and fat soluble) and minerals (bulk and trace elements) (WHO). Read more

Misreporting

Misreporting means giving an incorrect report of dietary intake.  One differentiates between intentional and unintentional misreporting. For example, unintentional misreporting happens when snacks or calorie-containing beverages are forgotten. Intentional misreporting relates to how we perceive foods. We tend to over-report perceived good foods like fruits and vegetables. But tend to underreport perceived bad foods, like things high in fat or sugar. Read more

Myelin

A protective layer of fat that insulates axons, gives white matter its colour, and accelerates signal transmission in the brain.

Necrosis

Necrosis is the medical term for the death of body tissue. Necrosis can occur because of illness, infection, injury, disease or lack of blood flow to your tissues.

Nitric oxide

Signalling molecule that regulates blood flow (via vasodilation), and tissue oxygenation.

Non- to minimally processed foods

Unprocessed (or natural) foods are the edible parts of plants (such as fruit, leaves, stems, seeds, roots) or from animals (such as muscle, offal, eggs, milk), and also fungi, algae and water, after separation from nature. Minimally processed foods are natural foods altered by methods that include removal of inedible or unwanted parts, and also processes that include drying, crushing, grinding, powdering, fractioning, filtering, roasting, boiling, non-alcoholic fermentation, pasteurization, chilling, freezing, placing in containers, and vacuum packaging. The distinction between unprocessed and minimally processed foods is not especially significant (FAO, 2019). Read more

Noncommunicable diseases

Noncommunicable diseases (NCDs), also known as chronic diseases, are a set of diseases that are the result of a combination of genetic, physiological, environmental and behavioural factors. NCDs are cardiovascular diseases (e.g. heart attacks and stroke), cancers, chronic respiratory diseases (e.g. asthma) and diabetes (WHO, 2021). Read more

Nutrient deficiency

Nutrient deficiency is also known as micronutrient deficiency, which describes the inadequate intake of a certain vitamin or mineral (e.g. vitamin A, iron) (WHO, 2021). Read more

Odds ratio (OR)

The odds ratio (OR) measures the association between an exposure and an outcome. It’s the odds that an outcome will occur in the exposed group divided by the odds of it happening in the non-exposed group. When there is no association between exposure and outcome, the OR is 1.0. Read more

Omnivore

A person who eats animal products, seafood, dairy and plant foods.

Paleo diet

A low-carbohydrate, nutrient-dense whole fresh food diet.  It includes fresh lean meats, fish, eggs, nuts, seeds, fruits and most vegetables. It excludes dairy, grains, sugars and most processed foods in general. Read more

Phytochemicals

Phytochemicals is an umbrella term, for a collection of compounds present in plants, including sulfur-containing compounds, nitrogen-containing compounds, carotenoids, polyphenols and tannins among others (Frank et al., 2020). Read more

Planetary health

Planetary health describes the achievement of the highest attainable standard of health, well-being and equity worldwide through judicious attention to the human systems (political, economic and social) that shape the future of humanity, and the Earth’s natural systems that define the safe environmental limits within which humanity can flourish (WHO, 2021). Read more

Plant-based diet

A plant-based diet consists of a diverse range of dietary patterns that emphasize foods derived from plant sources coupled with lower consumption or exclusion of animal products. Vegetarian diets form a subset of plant-based diets, which may exclude the consumption of some or all forms of animal foods. (WHO, 2021). See also Whole food, plant-based. Read more

Population Reference Intake (PRI)

The Population Reference Intake (PRI) describes the level of nutrient intake that is adequate for virtually all people in a population group (EFSA, 2017). Read more

Prevalence

Prevalence is the total number of disease cases in a population at a specific time. It’s usually expressed as a percentage of the population. It is not defined by a time interval, so it’s not a rate (compare with Incidence as they are often confused). Read more

Processed foods

Processed foods are defined according to NOVA classification. They include canned or bottled vegetables or legumes (pulses) preserved in brine; whole fruit preserved in syrup; tinned fish preserved in oil; some types of processed animal foods such as ham, bacon, pastrami, and smoked fish; most freshly baked breads; and simple cheeses to which salt is added (FAO, 2019). Read more

Processed meat

Processed meat is transformed through salting, curing, fermentation or smoking. These processes enhance flavour or improve preservation. Examples include hot dogs, ham, sausages, and canned meat and meat-based preparations. Read more

Prostaglandins

A group of lipids with hormone-like actions that the body makes at sites of tissue damage or infection. There are several different types of prostaglandins. In the blood vessels, they exhibit vasodilatory effects.

Protein Digestibility Corrected Amino Acid Score (PDCAAS)

The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is a method for evaluating protein quality. The PDCAAS has its limitations which is why FAO recommends to use the Digestible Indispensable Amino Acid Score (DIAAS) (FAO, 2013). Read more

Publication bias

Publication bias occurs when unfavourable information or negative results are withheld. It’s when the published studies don’t represent all studies undertaken in a given field. It’s a distortion in favour of the investigator. Read more

Randomization

Randomization allows you to control for all potential confounders. Subjects are randomly allocated to the treatment and control groups. Read more

Reactive Oxygen Species (ROS)

Compounds formed by the reduction of oxygen by the addition of electrons. ROS are damaging to cells and an imbalance toward the pro-oxidative state is often referred to as oxidative stress.

Reactivity / Observer effect

Werner Heisenberg postulated that each observation changes the observed reality. In other words, observing means intervention, also when observing oneself. Reactivity happens if someone alters their eating behaviour while reporting, for example. They may want to simplify the reporting process. They may want to avoid criticism from the observer, or they become more mindful when preparing and eating food. Read more

Recall bias

Recall bias results from a vague memory of past exposures. For example, 24-hour diet recalls rely on the interviewee’s memory. Can they recall precisely what they ate during the last 24 hours? Read more

Reductionist approach

Reductionism focuses on single nutrients rather than whole food or food patterns. It has been and continues today as the dominant approach in nutrition research. Yet, foods are more than the sum of their single nutrients. Thus, to understand diet-disease relationships, a more holistic approach is needed. Read more

Relative risks

Relative risk measures the association between exposure and outcome. It compares the risk of developing an outcome if exposed to the risk if unexposed. When there is no association between exposure and outcome, the RR is 1.0. Read more

Research agenda

The research agenda is the initial step in conducting research. It includes framing the research question and defining the study’s purpose. Read more

Response bias

Response bias refers to inaccurate or false answers to a question. Respondents desire to conform to perceived social norms. They want to finish survey questions quickly. Or they wish to perform in line with the research objectives. They might have guessed the aims of the study. Read more

Restriction

In restriction, you only include certain subjects. The study sample has the same values of potential confounding variables. It’s a way to control for confounders at the study design stage. Read more

Scientific hypothesis

The formulation and testing of a hypothesis are part of the scientific method. A scientific hypothesis proposes a tentative explanation of natural phenomena. It must be not only testable by direct experiments, but also falsifiable. So, it must be able to be proved wrong by conducting further experiments. Read more

Scientific method

It is the technique used to construct and test a scientific hypothesis. It involves observing, asking questions, and seeking answers through tests and experiments. It is not unique to any one field of science. Furthermore, it is applied across many areas. Read more

Selection bias

Selection bias comes from any error in selecting the study sample. It can be introduced either during the recruitment of subjects or while ensuring that they remain in the study. Sources of selection bias can be poorly defined inclusion and exclusion criteria. Or if some subjects are more likely to take part or be selected than others. In general, selection bias occurs in any non-random sample of the target population. Read more

Short Chain Fatty Acids (SCFAs)

SCFAs are Short Chain Fatty Acids. Gut microbes ferment or transform certain types of dietary fibre into SCFAs. There are three main types of SCFAs: acetate, propionate, and butyrate. SCFAs are vital for gut health: they repair a leaky gut, correct dysbiosis, regulate glucose homeostasis, and appetite, and reduce inflammation. Read more

Social desirability bias

A type of response bias. It occurs when people respond in a way they think will make them look good, instead of telling the truth. They wish to convey a desirable image or to seek approval. It affects interviews and surveys. For example, when asked about their eating habits, some people might conceal that they eat unhealthy foods. They downplay sugary drinks or fried foods while exaggerating fruits and vegetables. Read more

Stratification

Stratification is a statistical test to minimise the effect of confounding. The subjects are divided into different subgroups of the confounding variable, e.g. sex or age. Then the strength of the association is measured within each subgroup (called stratum). If the stratum-specific rates are uniform, they may be pooled to give a summary estimate. Read more

Stroke volume (SV)

The amount of blood that is pumped in one heartbeat. Stroke volume is a function of cardiac output.

Surrogate endpoints

In clinical trials, an indicator, or sign, is used in place of another to tell if a treatment works. In cancer trials, surrogate endpoints include a shrinking tumour or lower biomarker levels. They may be used instead of more robust indicators, such as more prolonged survival. Surrogate endpoints can be measured sooner. But they are not always accurate indicators of how well a treatment works. Read more

Systole

Pressure exerted on the arteries during ventricular contraction.

Tau tangles

Twisted protein tangles that form when tau inside neurons becomes hyperphosphorylated. These tangles cause neuronal damage and are closely linked to cognitive decline.

Telomeres

End points of DNA strands in chromosomes. These shorten as we age, and shorter telomeres than expected indicate more aged cells.

Tolerable Upper Intake Levels (UL)

The Tolerable Upper Intake Levels (UL) represent the maximum average daily intake level of nutrients considered to be unlikely to pose a risk of adverse health effects (EFSA, 2017). Read more

Top-down approach

A top-down approach equals a holistic approach. It’s from the general to the more specific. It studies the effects of dietary patterns rather than single foods or nutrients. Furthermore, it looks at what people usually eat. Read more

Trimethylamine N-oxide (TMAO)

MAO stands for Trimethylamine N-oxide. It’s a small organic compound produced in the gut. Microbes ferment or transform trimethylammonium-containing nutrients like L-carnitine (found in red meat) or certain choline (found in egg yolk and dairy products) into TMAO. TMAO is atherogenic and inflammatory. Read more

Ultra-processed foods

Ultra-processed foods are formulations of ingredients, mostly of exclusive industrial use, typically created by series of industrial techniques and processes (hence ‘ultra-processed’). Some common ultra-processed products are carbonated soft drinks; sweet, fatty or salty packaged snacks; candies (confectionery); mass produced packaged breads and buns, cookies (biscuits), pastries, cakes and cake mixes; margarine and other spreads; sweetened breakfast ‘cereals’ and fruit yoghurt and ‘energy’ drinks; pre-prepared meat, cheese, pasta and pizza dishes; poultry and fish ‘nuggets’ and ‘sticks’; sausages, burgers, hot dogs and other reconstituted meat products; powdered and packaged ‘instant’ soups, noodles and desserts; baby formula; and many other types of product. Ultra-processed foods are defined according to NOVA classification (FAO, 2019). Read more

Validity

Validity evaluates the quality of a study. It measures how well the results match established theories and other measures of the same concept. It assesses the extent to which the results measure what they are supposed to measure. The validity of a study is primarily determined by the experimental design. Internal and external validity are two ways of testing cause-and-effect relationships. Read more

Vasoconstriction

Purposeful narrowing of blood vessels to increase blood pressure and reduce flow.

Vasodilation

Purposeful widening of blood vessels to increase flow and lower vascular pressure.

Vegan diet

A vegan diet omits all animal products, including meat, dairy, fish, eggs and (usually) honey (WHO, 2021). See also Plant-based diet. Read more

Vegetarian diet

The term vegetarian diet is an umbrella term that includes the following:

• Lacto-vegetarian diets exclude meat, fish, poultry and eggs, but include dairy products such as milk, cheese, yoghurt and butter.
• Lacto-ovo vegetarian diets include eggs and dairy, but not meat or fish.
• Ovo-vegetarian diets exclude meat, poultry, seafood and dairy products, but allow eggs.
• Pesco-vegetarian (or pescatarian) diets include fish, dairy and eggs, but not meat.
• Semi-vegetarian (or flexitarian) diets are primarily vegetarian but include meat, dairy, eggs, poultry and fish on occasion, or in small quantities (WHO, 2021).

Visceral fat

Central fat accumulation within and around organs.

Waist to height ratio

Predictor of obesity-related cardiovascular disease risk. WtHR = waist circumference ÷ height. A WtHR >0.5 increases the risk. Read more

Well-being

Well-being is a positive state experienced by individuals and societies. Similar to health, it is a resource for daily life and is determined by social, economic and environmental conditions (WHO, 2021). Read more

Western diet

The Western diet is characterised by preserved and processed foods. It’s high in refined carbohydrates (e.g. white bread, biscuits, added sugars), saturated fats (e.g. meat and dairy) and salt. Read more

White matter

Brain tissue composed of myelinated axons. White matter is crucial for fast and efficient signal transmission in the brain.

Whole food, plant-based (WFPB)

Whole food, plant-based (WFPB) nutrition is an eating pattern emphasising plant foods in their whole form: vegetables, fruits, whole grains, legumes, nuts and seeds. Additives, added sugar and added salt are generally replaced with herbs and spices. For maximal health benefits, this diet excludes or limits animal products and food processing.