According to the Centers for Disease Control and Prevention (CDC), about 75% of the US adult population is overweight or has obesity. Approximately half of US adults have tried to lose weight in the last year.
The most common approaches have been to increase exercise (approximately 63% of dieters), eat less food (about 63% of dieters) and consume more fruits, vegetables and salads (about 50% of dieters). Most people have been unsuccessful, not necessarily in losing weight, but in keeping it off.
Advice about the best way to moderate energy intake and body weight is pervasive but also confusing as recommendations are wildly disparate; varying in the foods to be included or excluded, when and how much to consume and other lifestyle practices. Examples of recent popular approaches are categorized by diets that emphasize protein intake, reducing volume and mindful eating in the table below.
High Protein
Volumetric
Mindful eating
Distributed protein
High Palatability
Slower oral transmit time
High Fat
Meal Replacements
More oral processing
High Carbohydrate
Macrobiotic
Weight Watchers
Macronutrient ratio diets
Less variety
Plant-based
High Fiber
Smaller portions
Paleo
Raw Food
More Frequent Eating Events
Minimally processed
Low Energy Density
Less Frequent Eating Events
High water
Low glycemic
Morning eating
Mediterranean
Slowly digested
High thermogenic
Nordic
Nutrisystem
Food color
Dash
All have been useful for a small number of people, but none has been effective for all people. How is one to decide on the best approach?
Here are some points to keep in mind:
Overweight/obesity does not have a single etiology. There are contributions from the environment, genetics, lifestyle, diet and more. Each individual has a unique combination of these factors, so the appropriate remedy will be individual-specific. There is no one universal best diet.
The human body has better mechanisms to cope with a simple deficiency of energy than nutrient imbalances. Many popular diets do not provide all the required nutrients, so will likely lead to adverse health outcomes over time.
Wholesome nutrients consumed at levels ten times the recommended amount are considered drugs and are likely to exert adverse effects. Diets that emphasize single nutrients or foods will often lead to excessive intake of selected nutrients and are problematic.
If high or low levels of a nutrient or food is powerful enough to exert positive health effects, it is probably powerful enough to exert adverse effects.
Diet is the strongest determinant of energy intake and effects on weight gain or loss, but exercise is also critical for health, especially for helping to maintain lost weight.
So, what is the safest, most effective dietary approach for weight management outside of a clinical setting? It is to practice balance, moderation and variety. The amount of energy ingested should be modestly, not dramatically, lower than energy needs. A wide variety of foods should be consumed as this is the best way to ensure all nutrients will be included and not at excessive levels. This guidance is endorsed and embellished by the Dietary Guidelines for Americans. That guidance includes the following additional concepts:
Any food can fit. The key is to recognize an appropriate portion size and frequency of use. Food constituents, like added sugars, salt and fats, should be limited (not necessarily eliminated), while intake of vegetables, fruits and grain products should be enhanced (not ingested at excessive levels).
Many different combinations of foods will meet nutrient requirements. Thus, it is possible to design a dietary pattern that meets each individual’s flavor preferences, nutrient needs and budget without exceeding energy requirements.
Enjoy your food. A healthy diet that is not consumed will not be effective at meeting nutrient needs or weight management goals.
Recently there has been considerable excitement about new drugs that facilitate weight loss. Once clinical trials have established their safety and efficacy, they may be an option for some people. However, they are expensive and have adverse side effects. It is better to meet health goals by diet than by drugs.
Richard Mattes is a distinguished professor of nutrition science at Purdue University, adjunct associate professor of medicine at the Indiana University School of Medicine and affiliated scientist at the Monell Chemical Senses Center. His research focuses on the areas of taste function, hunger and satiety, food preferences, regulation of food intake in humans and human cephalic phase responses. At Purdue, Mattes is the head of the Ingestive Behavior Research Center. Outside of Purdue he was a member of the 2020 Dietary Guidelines Advisory Committee, is a past-president of the American Society of Nutrition and Secretary of the Rose Marie Pangborn Sensory Science Scholarship Fund. He has authored over 300 publications. Mattes earned an undergraduate degree in biology and a masters degree in public health from the University of Michigan as well as a doctorate degree in human nutrition from Cornell University. He conducted post-doctoral studies at the Memorial Sloan-Kettering Cancer Center and the Monell Chemical Senses Center.
