Perspective: Obesity-an unexplained epidemic

Area of Science:

• Nutrition Science
• Public Health
• Metabolic Research

Background:

• Obesity prevalence in US adults surged from 14% to 42% since 1980.
• The prevailing theory of increased energy intake is not supported by recent national data.
• National energy intake and availability data show plateaus or declines after 2000, even as obesity rates climbed.

Purpose of the Study:

• To challenge the overeating hypothesis for the ongoing obesity epidemic.
• To explore alternative biological hypotheses for escalating obesity.
• To highlight the need for new research and interventions.

Main Methods:

• Analysis of national data on energy intake and energy availability.
• Review of evidence on food processing, gut microbiome, and metabolic factors.
• Consideration of intergenerational risk transmission (epigenetics, noncoding RNAs).

Main Results:

• Energy intake data do not align with the continued rise in obesity post-2000.
• Existing errors in measurement cannot explain the observed trends without systematic bias.
• A complex interplay of factors including food processing and gut microbiota may be involved.

Conclusions:

• The current obesity epidemic may be driven by biological adaptations interacting with industrialized foods, rather than solely increased calorie consumption.
• Rethinking the primary drivers of obesity is critical for developing effective prevention and treatment strategies.
• Urgent investment in research and translation of existing science into interventions are necessary.