Morgan is a doctoral candidate in the field of clinical nutrition and nutritional neuroscience, having received her bachelors degree from Central Washington University.
Sears believes that keeping your diet in a specific macronutrient "Zone" will reduce the cellular inflammation that contributes to chronic disease and exacerbates obesity and related conditions. While caloric moderation ensures that weight will be lost on the Zone diet, Sears attributes weight loss to both caloric moderation and a reduction inflammation stemming from a macronutrient balance of 40% carbohydrate, 30% protein, and 30% fat. While there is undoubtedly a link between obesity and cellular inflammation, research thus far has pointed to excess body fat creating and exacerbating cellular inflammation, rather than inflammation directly causing obesity. However, some researchers speculate that the two may fuel each other: when excess fat accumulates and produces inflammatory chemicals, those chemicals may make it easier to gain weight. This theory has not, however, been proved by researchers. Sears believes that by maintaining a macronutrient composition of 40% carbohydrate, 30% protein, and 30% fat, dieters will reduce inflammation and optimize the cellular environment for weight loss.
The Zone Diet was created by a biochemist named Barry Sears, with the dual purpose of reducing inflammation and combatting obesity.
Many people will have a difficult time complying the Zone diet because of the meal planning requirements needed to meet the "Zone" meal balance requirements. Furthermore, the tedious aspects of this planning and limited flexibility may discourage dieters and lead to cravings that ultimately diminish motivation and reduce the likelihood long-term success.
The only costs to Zone dieters are groceries and the Zone diet guidebook. Online resources are also available.
Zone Dieters spend a lot of unnecessary time planning around the scientifically unproven 40-30-30 balance. Although all healthy eating and exercise initiatives require a time commitment, scientifically backed solutions should be given priority over time commitments that rely on faulty science.
The Zone diet offers a safe method for weight loss for the majority of dieters. The diet is nutritionally adequate, and provides healthy, "real" foods, rather than packaged diet food options. However, those with pre-existing medical conditions should always discuss dietary changes with their doctor or healthcare team.
The most contentious aspects of the Zone diet lie not with its methodology of Caloric reduction (which is required for long-term weight loss and maintenance, regardless of the specific diet), but with its belief system: research does not currently suggest the Zone 40-30-30 balance optimizes weight loss, or that inflammation is a root cause of obesity.
Benefits: The Zone Diet encourages the necessary caloric reduction to promote weight loss. It also provides structure to dieters seeking a specific dietary outline to obtain their goals.
Downsides: The diet has a questionable scientific base and may be too structured for some dieters, especially those with an aversion to meal-planning. It also lacks emotional support tools that are crucial for long-term behavioral change for some.
The Bottom Line: The Zone diet offers a reasonable chance of success; while there are better diets, Zone dieters will likely lose weight.