Dietary Intervention Messages: Restrict Fat vs. Promote Fruits & Vegetables

There are many approaches that nutritionists, registered dietitians, or other healthcare professionals use to get healthy eating messages across to the public or those in their care.  In some instances, these messages can be non-restrictive where healthy foods are promoted.  In other cases, the messages are restrictive where unhealthy foods are discouraged.  Differences in the effectiveness of these various strategies are understudied.

Researchers from Laval University in Quebec, Canada compared the effectiveness of two such strategies.  For their study, the investigators assigned 68 overweight or obese postmenopausal women to one of two dietary interventions: (1) a restrictive approach using messages to limit high-fat foods [LOFAT group] or (2) a promotional approach where messages encouraged addition of fruits and vegetables to the diet [HIFV group].  Both groups received 3 group sessions and 10 individual counseling sessions with a registered dietitian.  Changes in dietary intake, eating behaviors, and body size were determined at the beginning of the study, after 6 months when the intervention was completed, and after 12 and 18 months. The study investigators reported:

In the LOFAT group:

• Dietary intake of fat and overall energy was reduced at the end of the study period compared to the initial values.
• Energy and fat consumption remained lower than baseline as far out as 12 months after the study ended.
• Dietary restraint increased by the end of the study intervention period and remained high after 12 months of follow-up.
• Body weight was reduced by about 8 lbs after the first 6 months.

In the HIFV group:

• Consumption of fruits and vegetables increased by the end of the 6-month study intervention period.
• During the 12-month follow-up period, fruit and vegetable consumption returned to levels observed at the beginning of the study.
• No substantial changes in dietary restraint were observed in the HIFV group.
• Body weight decreased by about 4 lbs after the 6-month study period.

This is an interesting study comparing two approaches to healthy eating and weight loss.  Based on the results outlined above, it appears that the negative message strategy (messages to limit high fat foods) was more effective than the positive message strategy (encouraging fruits and vegetables).  The results suggest that while messages to increase consumption of fruits and vegetables are effective as long as they are delivered, people find it difficult to maintain high fruit and vegetable intake when the encouragement is withdrawn.  While both approaches resulted in similar weight loss success, the messages to restrict high fat food intake was apparently easier to follow.  Based on the study summary, it seems uncertain to me whether the inability of study volunteers to stick with their fruit and vegetable consumption was due to a failure of the positive message approach or the foods that were being encouraged.  Although the results of this study suggest that telling people what foods to avoid was more effective than telling people what foods to include, it is probably still important to educate consumers about healthy foods that can replace the less healthy high fat foods.

All of my soy protein shakes and milk protein shakes are low in total fat, making them an excellent choice if you are trying to limit fat intake.  They are a delicious and convenient part of my easy diet plan.