NHANES 1999–2000 and 2001–2002 included 2,690 nonpregnant women and 2,532 men aged 20 years or older with a household income ≤300% of the FPL. We excluded those participants for whom we were unable to determine their level of food insecurity (
n
=72), BMI (
n
=

640), waist circumference (
n
=

641), or diabetes diagnosis (
n
=

4). These exclusions left a total sample size of 4,423 participants, of whom 413 in the food secure category had diabetes, 134 in the mild food insecurity category had diabetes, and 47 in the severe food insecurity category had diabetes. Overall, food insecure individuals were younger, more likely to be from a racial or ethnic minority group, were poorer, and had achieved less educational attainment than food secure individuals (Table ).
| Table 1Baseline Characteristics of Eligible National Health Examination and Nutrition Examination Survey (NHANES) 1999–2002 Participants (n = 4,423) |
After adjusting for age, race/ethnicity, parity, income, educational attainment, and physical activity, women with mild food insecurity had higher obesity rates, mean BMI, and mean waist circumference than either food secure or severely food insecure women, whose values were similar to one another (Table ). For an average-height woman in the United States (162 cm),
24 the greater BMI among mildly food insecure women compared with food secure women (
Δ
=

2.0 kg/m
2) is equivalent to a weight difference of 5.2 kg. We did not observe a relationship between food insecurity and obesity among men. Unadjusted results were similar to adjusted results for both women and men.
| Table 2Adjusted Association Between Food Insecurity and Obesity Among Women and Men in the United States |
The estimated prevalence of diabetes in the food secure, mildly food insecure, and severely food insecure categories was 11.7%, 10.0%, and 16.1%. Compared to adults who were food secure, the odds of diabetes was 1.2 (95% CI 0.8–1.8) for those with mild food insecurity and 2.1 (95% CI 1.1–4.0) for those with severe food security after adjusting for gender, age, race/ethnicity, parity, income, family history of diabetes, education, and physical activity (Table ). This relationship persisted after further adjusting for BMI.
| Table 3Relationship Between Food Insecurity and Diabetes Mellitus in the United States |
Adjusting for waist circumference instead of BMI did not alter the observed relationship between food insecurity and diabetes. Compared to the food secure category, the odds of diabetes after adjusting for all other potential confounders including waist circumference was 1.0 (95% CI 0.7–1.5,
p
=

.8) in the mildly food insecure category and 2.0 (95% CI 1.1–3.6,
p
=

.03) in the severely food insecure category.
We calculated mean daily caloric and carbohydrate intake to determine whether differences in diet might mediate the observed relationship between food insecurity and diabetes. Among women, the estimated mean daily caloric intake was 1,780 kcal/day in the food secure category, 1,822 kcal/day in the mild food insecurity category (
p
=

.3 compared to food secure women), and 1,876 kcal/day in the severe food insecurity category (
p
=

.2 compared to food secure women). Among men, the estimated mean daily caloric intake was 2,549 kcal/day in the food secure category, 2,759 in the mild food insecure category (
p
=

.09 compared to food secure men), and 2,543 in the severe food insecure category (
p
=

.9 compared to food secure men). Among women, estimated mean carbohydrate intake was 233 g/day in the food secure category, 237 g/day in the mild food insecurity category (
p
=

.4 compared with food secure women), and 242 g/day in the severe food insecurity category (
p
=

.4 compared with food secure women). Among men, mean carbohydrate intake was 314 g/day in the food secure category, 339 g/day in the mild food insecure category (
p
=

.09 compared with food secure men), and 311 g/day in the severe food insecure category (
p
=

.8 compared with food insecure men).
After adding daily caloric and carbohydrate intake to the models including gender, age, race/ethnicity, parity, income, family history of diabetes, educational attainment, level of physical activity and BMI, mild food insecurity was associated with a 1.1 (95% CI 0.7–1.6,
p
=

.7) higher odds of diabetes and severe food insecurity was associated with a 2.2 (95% CI 1.2–4.2,
p
=

.01) higher odds of diabetes.