More than one in four children starting reception class in Cumbria have excess weight and obesity, according to Cumbria's Director of Public Health.
The problem progresses in Copeland, which has the highest proportion, 41%, of overweight and obese children by the time they finish primary school.
Figures also show that two in three adults in Cumbria are overweight.
Cumbria County Council's Public Health department is hosting a 'Healthy Weight Summit' to tackle obesity in the county.
Over 100 representatives from around Cumbria have gathered to discuss how the county can become more active to reverse the worrying trends.
Colin Cox said if nothing is done to help tackle obesity people's health will suffer:
Obesity is considered to be one of the most serious public health challenges of the 21st century.