Testing the Effectiveness of Coping With Cancer in the Kitchen

Primary outcomes

1. Knowledge about the role of a plant-based diet in cancer risk reduction

   Time frame: 9 weeks

   Change from baseline in knowledge about role of consuming a predominantly plant-based diet and cancer risk. Participants rated their agreement (1 = Strongly disagree; 5 = Strongly agree) with six custom items developed by the research team, e.g., "I understand the benefits of consuming whole grains versus processed grains". A composite score was calculated as the average of the 6 ratings (range 1-5; Cronbach's alpha=.80).

2. Knowledge about the role of a plant-based diet in cancer risk reduction

   Time frame: 15 weeks

   Change from baseline in knowledge about role of consuming a predominantly plant-based diet and cancer risk. Participants rated their agreement (1 = Strongly disagree; 5 = Strongly agree) with six custom items developed by the research team, e.g., "I understand the benefits of consuming whole grains versus processed grains". A composite score was calculated as the average of the 6 ratings (range 1-5; Cronbach's alpha=.80).

3. Confidence preparing a variety of plant-based foods

   Time frame: 9 weeks

   Change from baseline in confidence to prepare a variety of plant-based foods. Participants indicated "How sure are you that you could prepare the foods listed below in a tasty way?" (1 = Very unsure; 5 = Very sure). The 14-item scale included: 4 whole grains; 4 beans, seeds and legumes; 3 green leafy vegetables; and 3 mixed foods, e.g. healthy one-pot meals. A composite score was calculated as the average of the 14 items (range 1-5; Cronbach's alpha=.75).

4. Confidence preparing a variety of plant-based foods

   Time frame: 15 weeks

   Change from baseline in confidence to prepare a variety of plant-based foods. Participants indicated "How sure are you that you could prepare the foods listed below in a tasty way?" (1 = Very unsure; 5 = Very sure). The 14-item scale included: 4 whole grains; 4 beans, seeds and legumes; 3 green leafy vegetables; and 3 mixed foods, e.g. healthy one-pot meals. A composite score was calculated as the average of the 14 items (range 1-5; Cronbach's alpha=.75).

5. Skills to practice a plant-based diet

   Time frame: 9 weeks

   Change from baseline in skills to practice a plant-based diet. Participants rated their agreement (1 = Strongly disagree; 5 = Strongly agree) with five custom items developed by the research team, e.g., "I am confident that I can create a kitchen environment that makes it easier to store, prepare, and consume fruits, vegetables, whole grains, and beans."; the average of the five ratings was calculated to create a skills composite score (range 1-5; Cronbach's alpha=.88).

6. Skills to practice a plant-based diet

   Time frame: 15 weeks

   Change from baseline in skills to practice a plant-based diet. Participants rated their agreement (1 = Strongly disagree; 5 = Strongly agree) with five custom items developed by the research team, e.g., "I am confident that I can create a kitchen environment that makes it easier to store, prepare, and consume fruits, vegetables, whole grains, and beans."; the average of the five ratings was calculated to create a skills composite score (range 1-5; Cronbach's alpha=.88).

7. Barriers to eating more fruits and vegetables and whole grains

   Time frame: 9 weeks

   Change from baseline in barriers to eating more fruits and vegetables and whole grains. We adapted items from an existing barriers instrument to measure perceived barriers to eating more fruits and vegetables (F&V) (average score of 15 items; Cronbach's alpha = .89) and whole grains (average score of 14 items; Cronbach's alpha = .83). Participants were asked the general question, "Listed below are some common reasons why people don't eat more servings of vegetables and fruits each day. Indicate whether or not this is a reason for you by marking how much you agree or disagree." (1 = Strongly disagree; 5 = Strongly agree). In addition, using the same list of possible reasons (excluding spoil too quickly), participants indicated whether it was a common reason they didn't eat more servings of whole grains. Example reasons included: take too much time to prepare; my family doesn't like them; hard to find a variety of good ones.

8. Barriers to eating more fruits and vegetables and whole grains

   Time frame: 15 weeks

   Change from baseline in barriers to eating more fruits and vegetables. We adapted items from an existing barriers instrument to measure perceived barriers to eating more fruits and vegetables (F&V) (average score of 15 items; Cronbach's alpha = .89) and whole grains (average score of 14 items; Cronbach's alpha = .83). Participants were asked the general question, "Listed below are some common reasons why people don't eat more servings of vegetables and fruits each day. Indicate whether or not this is a reason for you by marking how much you agree or disagree." (1 = Strongly disagree; 5 = Strongly agree). In addition, using the same list of possible reasons (excluding spoil too quickly), participants indicated whether it was a common reason they didn't eat more servings of whole grains. Example reasons included: take too much time to prepare; my family doesn't like them; hard to find a variety of good ones.