Table 3 Overview of the themes and subthemes with quotations of FANLIt

Theme 1

Cognitive: Food and nutrition knowledge

Knowledge and understanding on meaning, types, components and food sources, Thai healthy index, food safety, amount, sources and functions of nutrition, food label, and effects of food and nutrition on health

“It is knowledge and understanding of food and nutrition on safe food consumption which is beneficial to the body”. (IDPch₃)

“Students should be able to identify types of food and food safety. They should be able to tell us nutrients of the food their consumed, and the extent they are beneficial to our body. They should also read food label.”. (IDP₃)

Subtheme: Food knowledge

Fundamental knowledge on food, including definition, types, ingredients, contaminants, sources of food and food-based dietary guidelines

“For the first issue, the literacy of food should be composed of definition, physical components of food, types, sources, knowledge and extent regarding types of nutrients for children at this age, according to food-based dietary guidelines.” (IDPo₂)

Subtheme: Food Understanding

Understanding the thinking and utilising fundamental concept on food, including safe food and effects of food on health

“When students can explain that our health is related to food we consumed, such as mentioning that excessive sugar intake might cause diabetes in the future…” (IDP₃)

Subtheme: Nutrition knowledge

Fundamental knowledge of nutrition, including types, amount, sources, functions of nutrients and knowledge in reading nutrition facts

“Children understand that food is fundamentally necessary for our health, such as strengthening our bodies, increasing immunity with less chance of having illness and infection. It can also remedy illness.” (IDPo₂)

“Nutrition literacy are knowledge on functions of nutrients, including creating and mending cells that affect the working of our bodies.” (IDPo₂)

“Children should be educated on nutrition, including types of nutrients, amount of nutrients they should get, sources of nutrients and nutrition information on food label. “ (FGPt₄)

Subtheme: Nutrition understanding

Understanding the thinking and utilising fundamental knowledge regarding food nutrition, nutrition fact label and effects of nutrition on health

“Students should understand nutrients that are necessary for our bodies, and how the amount of the nutrients affects our bodies. They should also know the meaning of nutrition flag.” (FGDPt₂)

“The meaning of food and nutrition literary is deeper than knowledge. It refers to not only having knowledge regarding food and nutrition, but also having understanding about them.” (IDPo₃)

“…accessing, understanding and utilizing. They should also understand food and nutrition to make accurate decision.” (IDA₂)

“The main focus is on health literacy, but the content is related to food and nutrition. Food and nutrition are the context to evaluate problems and issues. The actions of accessing, understanding and evaluating issues regarding food and nutrition of children should be continuous.” (IDA₃)

“Children should understand food information on the nutrition label to select appropriate food.” (FGPt₁)

““They should understand types of nutrients that strengthen their bodies, and know types of nutrients that may cause illness.” (FGPch₁)

Theme 2

Skill: Functional food and nutrition literacy

Food and nutrition information accessing, selection, preparation, cooking and planning of daily food and nutrition

“Food and nutrition literacy is defined as the ability to have intellectual and social skills to search for information from sources and understand all information.” (IDPo₁)

Subtheme: Accessing to food and nutrition information

Ability to search, ask for information on food and nutrition from sources, such as media and people

“Intellectual and social skills to search for information from sources for adolescents are defined as the ability to search for information to deal with health. They should also able to do the searching in English via the Internet and digital form.” (IDPo₁)

Subtheme: Food selection

Ability to select both fresh and ready-to-eat food which is high quality and beneficial for our health

“Students have knowledge on type, price, quality, freshness of food to make a selection of appropriate food for themselves.” (IDPo₁)

“They should have accurate knowledge and should be aware of food that is beneficial and contaminant-free and organic, and utilise such skills to select, prepare and cook actual food.” (IDPo₃)

Subtheme: Food preparation skills

Ability to prepare and cook, including food preparing, cooking healthy food, using cooking utensils, and food preserving

“Cleanliness and food preservation should be maintained, such as storing leftovers in the fridge, and heating up before having it. Meat should be stored in the freezer or being sun-dried.” (IDPt₅)

“It is the ability to cook various food, such as steaming, grilling, barbecuing, boiling or stir-frying.” (FGDPch₁)

“It is the ability to prioritize importance when dealing with their own food.” (IDPo₂)

“It is planning and aiming for having healthy food. They should also realise that each group of food has different essences to our health, resulting in different amounts of their intakes.” (IDPhph₁)

Theme 3

Skill: Interactive food and nutrition literacy

Informing, inquiring, asking for advice, communicating, information exchanging, discussing food and nutrition with peers, family, academics, healthcare providers or other people, giving advice and convincing others to consume healthy food

“Food and nutrition literacy for adolescents includes interactive and critical levels. They should search for more information, i.e. they should be brave to ask questions.” (IDPo₁)

“Communication and information exchanging between themselves and others is important as they could think and analyze before making a decision on the practice of the food and nutrition.” (IDPo₂)

Subtheme: Communication with others (e.g., peers, family, academics, healthcare providers) on food and nutrition

Ability to communicate, inform, inquire or ask for advice regarding food and nutrition from others

“It is the ability to communicate, access, and gain knowledge from service providers. Eventually, understanding the thinking process, analysing, categorising, synthesising and evaluating are the processes of creating new knowledge. We should be aware and could apply this knowledge to prevent illness. We should also be able to solve problem that might arise in the future.” (IDA₁)

“They should have sources where advice could be given, such as health mentor who can deal with food and nutrition.” (IDPo₁)

“We can ask advice from health education teachers, or doctors with specialization in nutrition.” (FGPch₁)

Subtheme: Sharing and discussing regarding food and nutrition with others

Ability to exchange information, discuss, express opinion regarding food and nutrition, give advice and convince others to consume healthy food

“We may need skill to deal with our own health, and could accurately pass on this skill at individual level, and increase health quality.” (IDPo₂)

“Knowledge and understanding food and nutrition regarding safety of food consumption might be beneficial to our health, and might change consuming behaviour that is suitable for our bodies. We can also give others advice.” (IDPch₃)

Theme 4

Skill: Critical food and nutrition literacy

Ability to evaluate and select information regarding food and nutrition, apply such information to make a decision on food consumption according to food-based dietary guidelines, deal with food budgeting, including expense management and comparison on food price when consuming healthy food

“After the students receiving information, they should be able to tell which information is accurate. Besides accessing information from all sources, they should be able to filter, examine and understand food and nutrition. This should result in accurate decision when selecting food to consume. The practice is important as food and nutrition literacy has the main focus on the implementation.” (IDA₂)

“Food and nutrition literacy in adolescents includes interactive and critical levels. When in doubt, they should ask question and argue which might lead to the change in behavior.” (IDPo₁)

Subtheme: Information utilising in decision making

Ability to examine and analyse to evaluate and select information regarding food and nutrition from sources to achieve the aim of healthy food consumption

“Critical literacy refers to an ability to filter and select information from media, and evaluate it. At the moment, we have various sources of information on food on social media. This affects the decision making on food selection of people.” (IDPo₂)

“I wholeheartedly agree with decision making as it is related to the practice in thinking and examining. This might yield wisdom to believe in the message.” (IDA₂)

“It is a matter of intelligence, starting from accessing, understanding, analyzing, synthezing, evaluating and applying.” (IDA₃)

“When there is load of information, I will select the information by reading the websites, comparing them, and analyzing the possibility of it. This should help me make a decision on believing in them.” (IDS₉)

Subtheme: Healthy food selection

Ability to make a decision to select healthy food

“Food literacy concerns the literacy in selecting types, price, quality and freshness in terms of food safety and hygiene. The last issue is accurate decision that leads to the practice on food selection.” (IDPo₁)

“It is the ability to search and study information that is necessary in food we are taking. It is also the ability to realize the extent the food is beneficial for our health and make a decision on food that is appropriate for our health.” (IDA₄)

“It is the ability to select and make a decision to buy and have food by reading nutrition label. It is also the ability to read the amount of sugar, sodium and fat to provide energy and benefits to our health.” (IDPch₁)

Subtheme: Effective budgeting

Ability to manage costs on food, including expense management, and comparison on food that is healthy and worth consuming

“It is the effort to select food that is healthy although it might be more expensive than other food, or the effort to buy healthy food despite limited budget.” (IDP₄)

“The scope of health knowledge regarding food includes pricing and cost of food consumption, i.e. the food is worth buying, appropriate and healthy.” IDPo₂

“In selecting food, we need to consider whether it is fresh. For some food, getting it from market might be cheaper and fresher. I will also consider if it is contaminant-free, then compare the prices.” (FGDSn₂)