Question

Research suggests that people who keep food records

Answer 1

Research indeed suggests that people who're keeping food records are also those who will be more effective in different weight loss strategies - b. 

Losing weight strategically through the help of keeping a food record also makes it more probable that you will lose weight. 

Answer 2

Research suggests that people who keep food records tend to lose weight effectively.

$\sf\ Answer:\ B)\ tend\ to\ lose\ weight\ effectively$