① Research shows that in developed countries, more affluent and educated people tend to consume higher-quality diets — including more fruits and vegetables, fish and whole grains. On the contrary,economically disadvantaged people report diets that are nutrient-poor and energy-dense. They are less likely to have food-purchasing habits that conform to public health recommendations.

② These  dietary  differences  are  often  accompanied  by  higher  rates  of obesity  and   diabetes  among  lower-income  people.  This  relationship  between  social  class  and  diet quality and health is extensively documented. However, the research does not explain why this is the case — a question that has significant implications for designing effective policies and initiatives to improve diets and prevent chronic diseases.

③ Public-health initiatives to promote healthy diets often focus on providing nutrition   education and recipes (食谱).These  approaches, however, often presume less food literacy (i.e.food knowledge and skills) among low-income people. Are unhealthy diets really the result of poor choices, limited food skills and knowledge?

④ Research suggests that adults in food-insecure households are just as likely as those in   food-secure households to adjust recipes to make them more healthy. They are also just as proficient in food preparation and cooking skills. There is no indication that increasing food skills or budgeting skills will reduce food insecurity.

⑤ Instead,disadvantaged groups are constrained by their economic, material and social   circumstances. For example,low income is the  strongest predictor of food insecurity in Canada, where one in eight households experiences insufficient access to nutritious foods.

⑥ It’s well-established that  food prices  are  an  important  determinant  of food  choice.   Low-income households report that they find it difficult to adopt dietary guidelines because food prices are a barrier to improving their diets.

⑦ When researchers estimate the cost of diets people actually eat, higher-quality diets are typically more costly.

⑧ While this may be so, it does not, in itself, prove that healthy diets are necessarily   more  expensive  or  cost-prohibitive.  After  all,  not  all  socioeconomically  disadvantaged people consume poor diets.

1.1.What can we learn from research on diets in developed countries?

A Dietary recommendations are not fit for underprivileged people.

B People from different social groups vary in their dietary habits.

C People’s choice of food depends on their individual taste.

D There is no consensus on what high-quality diets are.

解析：选B。B 细节理解题。依据文章第①段首句：“Research shows that in developed countries, more affluent and educated people tend to consume higher-quality diets...On the contrary, economically disadvantaged people report diets that are nutrient-poor and energy-dense.” 明确说明不同社会群体（富裕与贫困人群）的饮食习惯存在差异。选项B准确概括了这一研究发现，其他选项在文中均未提及或与原文不符。故选B。

2.2.What does the author say is important in formulating policies to improve diets and health?

A A better understanding of the relationship between social class and health.

B A greater emphasis on studying the cause of obesity and chronic diseases.

C Prioritizing the provision of better nutrition for lower classes.

D Designing education programs and initiatives on public health.

解析：选A。A 推理判断题。文章第②段末尾指出：“However, the research does not explain why this is the case — a question that has significant implications for designing effective policies...” 表明当前研究尚未解释社会阶层与饮食健康的关系，而理解这一原因对制定有效政策至关重要。由此可推断，作者认为深入理解社会阶层与健康的关系是政策设计的关键，选项A符合这一逻辑。其他选项未直接回应“解释原因”这一核心问题。故选A。

3.3.What does research reveal about adults in food-insecure households?

A Their eating habits need to be changed.

B Their food literacy has been improving.

C They do not pay much attention to their food recipes.

D They do not lack food knowledge or budgeting skills.

解析：选D。D 细节理解题。第④段明确指出：“adults in food-insecure households are just as likely...to adjust recipes to make them more healthy. They are also just as proficient in food preparation and cooking skills.” 说明食物不安全群体的食品知识和技能并不缺乏，且“no indication that increasing food skills or budgeting skills will reduce food insecurity”进一步强调他们不缺预算管理能力。选项D与此完全对应，其他选项与原文矛盾。故选D。

4.4.What would help improve food security among the disadvantaged groups in Canada?

A Teaching them budgeting skills.

B Increasing their food choices.

C Enabling them to have more access to nutritious foods.

D Taking more effective measures to increase food supplies.

解析：选C。C 推理判断题。第⑤段提到低收入是食物不安全的主要预测因素，并指出“one in eight households experiences insufficient access to nutritious foods”。结合第⑥段“food prices are a barrier to improving their diets”，可推断解决食物安全问题的核心是增加对营养食物的获取，而非单纯提供教育或技能培训。选项C紧扣“access to nutritious foods”这一关键障碍，其他选项未针对根本原因。故选C。

5.5.What does the author suggest disadvantaged people do to improve their health?

A Adopt a positive attitude towards dietary guidelines.

B Choose diets that are both healthy and affordable.

C Make sure to purchase healthy foods on the internet.

D Change their eating habits and consumption patterns.

解析：选B。B 推理判断题。文章最后三段强调健康饮食不一定昂贵，并提到“recipes for ‘eating well on a budget’”。作者通过指出“not all socioeconomically disadvantaged people consume poor diets”和列举既健康又经济的饮食选择，暗示弱势群体应选择兼顾健康与经济性的饮食。选项B准确概括了这一建议，其他选项或偏离经济性限制（如C、D），或未涉及具体行动方向（如A）。故选B。