Meaning: 'Fruits and vegetables' refer to plant-based foods that are rich in vitamins, minerals, and fiber, essential for a healthy diet.

Wrong options:

• meats and sweets: 'Meats and sweets' suggests a combination that includes unhealthy options, which contradicts the idea of a balanced diet focused on health.
• oils and fats: 'Oils and fats' can be part of a diet but do not provide the same range of nutrients as fruits and vegetables, making them less suitable in this context.
• sugars and salts: 'Sugars and salts' are generally considered unhealthy in excess and do not contribute positively to a balanced diet, thus not fitting the context.

Correct answer: increase

Explanation: 'Increase' is the correct verb that indicates a positive change in the intake of essential fiber and nutrients, fitting grammatically and contextually with the sentence structure.

Meaning: 'Increase' means to become greater in amount or degree, which is desirable when discussing nutrient intake.

Wrong options:

• decrease: 'Decrease' implies a reduction, which contradicts the intention of improving nutrient intake.
• stagnate: 'Stagnate' suggests no change, which is not appropriate in the context of making healthier food choices.
• fluctuate: 'Fluctuate' indicates variability, which does not align with the goal of consistently improving nutrient intake.

Correct answer: boosting

Explanation: 'Boosting' is the correct gerund form that indicates an enhancement in metabolism, fitting well with the context of hydration's role in health.

Meaning: 'Boosting' means to increase or improve something, in this case, metabolism and digestion.

Wrong options:

• hindering: 'Hindering' means to obstruct or impede, which is the opposite of what hydration does for metabolism.
• ignoring: 'Ignoring' implies neglect, which does not relate to the positive effects of hydration on health.
• suspending: 'Suspending' suggests a temporary halt, which does not accurately describe the continuous benefits of hydration.

Correct answer: long-term

Explanation: 'Long-term' is an adjective that describes benefits that are sustained over time, aligning perfectly with the context of gradual dietary changes.

Meaning: 'Long-term' refers to effects or benefits that persist over an extended period, emphasizing the lasting impact of dietary changes.

Wrong options:

• immediate: 'Immediate' suggests instant results, which does not accurately reflect the gradual nature of dietary improvements.
• negligible: 'Negligible' means insignificant, which contradicts the idea of meaningful benefits from dietary changes.
• adverse: 'Adverse' indicates negative effects, which is contrary to the positive outcomes expected from a balanced diet.