Chapter 2 - Nutrition Sciences & information Library

Summary - Scientific Method, different types of research and levels of evidence, correlation vs causation, bias and limits, identifying credible sources, how nutrition claims are backed by evidence


Objectives -

1. Identify the sequential steps of the scientific method, and understand the importance of reporting research results in peer-reviewed journals and the value of scientific consensus.

2. Describe the different types of research studies used in nutrition, including the quality of evidence, advantages, and limitations of each.

3. Describe some of the limitations of nutrition research, including the challenges of studying complex dietary patterns and the influence of industry funding.

4. Identify the training and experience that leads to expertise in the field of nutrition, as well as career opportunities in the field.

5. Evaluate sources of nutrition information and distinguish between credible sources and those that are inaccurate or biased.


2.1 - Introduction to Nutrition Science and Information Literacy

How do you find accurate evidence for food claims?

developing skills on information literacy, scientific method, researh types, sources


2.2 - The scientific method

  1. observation - research question to investigates

  2. hypothesis - educated guess, explain the observation and can be tested through scientific experiments

  3. experiments - designs and conducts experiment, what has already been done, review of published research to advance research

  4. analysis - analyze data that support of refute hypothesis, if refuted, a new experiment must be conducted. if hypothesis is supported, the researchers will design new experiments to further support the hypothesis

  5. conclusion, if many experiments support a hypothesis, we can ge to a conclusion/theory


conclusions that are supported by evidence usually opens the door to new guestions

mistakes and biases can lead to inaccurate experiment conclusions

usually takes many people looking at the same questions to reach a consensus in which everyone agrees about the data


History of the scientific method at work

Early 1800s - swiss guy Jean-Francois Coindet observed that eating seaweed would cure enlarged neck. hypothesized that seaweed had iodine and could use that directly, which he did, and the hypothesis turned out to be correct.


Mid 1800s - french chemist hypotheses that places far from ocean meant people werent getting their iodine. they started giving out iodine pills and 80% of children with goiter were cured. some said that it was a disease, others as a mean to not fight in the military


Early 1900s - swiss doctor bayard prososed iodizing salt to help people that commonly got goiter. In a trial, families were given half a year for use. results showed reduction of goiter.


conclusion was that it took almost a century and many scientists too come up with an effective treatment for goiter until the public regonixed the treatment. uncertainty is part of the scientific process. consensus is when the majority agrees



Reporting scientifc work -

communicating is important, most scieentist publish their work in scientific journals for people to see


peer-reviewed journals are papers reviewed by peers. quality control


2.3 - types of research