Bologna: what a slice holds and what processed meat does

A 12-week randomized trial put 113 healthy adults aged 18 to 50 on a weekly diet of four 5.3 oz (150 g) servings of red meat, three 1.8 oz (50 g) servings of processed meat and one of poultry. It raised fecal water genotoxicity, a measure of DNA damage, by about 16 points on a percent scale (95% CI 4.6 to 27.3). A pesco-vegetarian diet showed no significant change. The trial was open label, it measured a marker in stool rather than cancer, and processed meat was only part of the diet. One 0.99 oz (28 g) slice of bologna in the USDA record gives about 79 calories, 6.7 g fat, 2.9 g protein and 308 mg sodium, and a sandwich portion is two slices, 56 g. That is one recipe code, and brands differ. USDA analysis of six classic bologna samples found saturated fat anywhere from 3.8 to 10.8 g per 3.5 oz (100 g). Reduced-fat bologna has 14.8 g fat and 821 mg sodium per 3.5 oz (100 g), against 23.77 g and 1100 mg for regular.

The numbers, per 3.5 oz (100 g)

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• Reduced-fat bologna has about 38% less fat and 25% less sodium than regular bologna per 3.5 oz (100 g) in the USDA FNDDS records, at 204 versus 281 calories. — US food codes Bologna (2706176) and Bologna, reduced fat (2706177) Evidence E source
  Fat 14.8 vs 23.77 g, sodium 821 vs 1100 mg, energy 204 vs 281 calories, protein 11.8 vs 10.34 g per 3.5 oz (100 g)

What a real portion looks like

• One 0.99 oz (28 g) slice of bologna provides about 79 calories, 6.7 g fat, 2.9 g protein and 308 mg sodium, and a two-slice sandwich portion (56 g) doubles that, in the USDA FNDDS record. — US food code Bologna, FNDDS 25220410 Evidence E source
  Per 100 g: 281 calories, fat 23.77 g, protein 10.34 g, sodium 1100 mg; slice 28 g, regular sandwich 56 g, large sandwich 84 g

What cooking and storage change

• Lab tests of 1132 US cured meats found large-diameter cooked sausages, a class the paper does not tie to bologna by name, held about 10 ppm residual nitrite on average, and nitrite kept falling to very low levels over 45 days of chilled storage. — 1132 processed meats from state meat-processor competitions in California, Pennsylvania and Wisconsin; storage study on 113 products (n = 1132) Evidence D source
  Mean residual nitrite 10.1 ppm in large diameter cooked sausage (all processed meats 13.7 ppm); nitrite fell during 45-day refrigerated display while nitrate stayed stable or rose

What it does to your health

• In a 12-week RCT in 113 healthy adults, a diet with red meat and three 1.8 oz (50 g) servings of processed meat a week raised fecal water genotoxicity by about 16 points on a percent DNA damage scale, while a pesco-vegetarian diet did not. — healthy adults aged 18-50, free-living, 12 weeks; meat diet 4 x 150 g red meat, 3 x 50 g processed meat, 1 x 150 g poultry weekly (n = 113) Evidence B source
  Fecal water genotoxicity +15.97% DNA damage (95% CI 4.61 to 27.32, p = 0.006) after meat-based diet; no within-group change on pesco-vegetarian diet
• Observational data from 31 cohorts and nearly 2 million adults link each extra 50 g a day of processed meat, about two slices of bologna, with a 15% higher risk of type 2 diabetes. — 1 966 444 adults in 31 cohorts from 20 countries, median follow-up 10 years (n = 1966444) Evidence C source
  HR 1.15 (95% CI 1.11-1.20) per 50 g/day processed meat
• Observational data from cohorts link each daily serving of processed meat with 0.57 lb (0.26 kg) more weight gain a year, with low certainty. — adults in 3 cohort studies with measured weight (n = 381291) Evidence C source
  +0.26 kg/year per daily serving (95% CI 0.03-0.48), I2 93%, GRADE low

Safety, limits and interactions

• According to CDC, people at higher risk of Listeria, including pregnant people, should avoid unheated cold cuts and eat them only reheated to 165F or until steaming hot. — groups at higher risk of listeriosis, including pregnant people (US federal advice) Evidence E source
  Reheat deli meat and cold cuts to 165F (74C) or until steaming hot

What people believe that the data does not support

• In an online grocery RCT with 3518 US adults, red meat warning labels, a 30% tax or both cut processed meat picks by 0.12 to 0.26 items per basket. — US adults in a naturalistic online grocery store, randomized to control, warning labels, 30% tax, or both (n = 3518) Evidence B source
  Processed meat items vs control: labels -0.12 (95% CI -0.22 to -0.02), tax -0.16 (-0.26 to -0.06), labels + tax -0.26 (-0.36 to -0.16)
• In a randomized taste study of 115 young men, labeling bologna as Light (10% fat) made it taste less salty and fatty but no less pleasant than Regular (20% fat). — young men, labeled vs unlabelled tasting of regular and reduced-fat bologna (n = 115) Evidence B source
  Labeled Light Bologna rated lower in saltiness and fattiness after tasting; pleasantness and juiciness not significantly different

What is still unknown

• Saturated fat in bologna varies widely between samples, from 3.8 to 10.8 g per 3.5 oz (100 g) across six classic bologna samples and 6.9 to 11.3 g across three beef bologna samples analyzed by USDA. — USDA Foundation Foods samples of Bologna, classic (6) and Bologna, beef (3) Evidence E source
  Classic mean 7.40 g (range 3.82-10.78, median 7.01); beef mean 9.21 g (range 6.93-11.29, median 9.41) per 3.5 oz (100 g)

The bottom line

The disease links are observational. Across 31 cohorts with nearly 2 million adults followed for a median of 10 years, each extra 50 g a day of processed meat went with a 15 percent higher risk of type 2 diabetes (HR 1.15, 95% CI 1.11 to 1.20). Three cohorts with measured weight linked each daily serving with 0.57 lb (0.26 kg) more gain a year (95% CI 0.03 to 0.48), and the authors rate that certainty low because the studies disagreed widely. Nitrite fades in the fridge. Lab tests of 1132 US cured meats entered in meat-processor competitions found about 10 ppm residual nitrite on average in large cooked sausages, the class our researcher placed bologna in. Nitrite kept falling over 45 days of chilled display while nitrate held steady or rose slightly. Who should be careful: CDC advises pregnant people and others at higher risk of Listeria to eat deli meat and cold cuts only reheated to 165F (74C) or until steaming hot. CDC does not name bologna in that advice. We have no card on drug interactions or on children for bologna. Labels shift what people pick and taste. In an online grocery experiment with 3518 US adults making hypothetical purchases, warning labels, a 30 percent tax or both led to 0.12 to 0.26 fewer processed meat items per basket. In a 1998 study of 115 young men, calling a bologna Light made it taste less salty and less fatty, with no loss of pleasantness.

Sources

1. bolo-r7-02 · dataset
   Bologna (fdc 2706176): Energy 281 KCAL · Total lipid (fat) 23.77 G · Sodium, Na 1100 MG · Protein 10.34 G per 100 g | Bologna, reduced fat (fdc 2706177): Energy 204 KCAL · Total lipid (fat) 14.8 G · Sodium, Na 821 MG · Protein 11.8 G per 100 g
   USDA FNDDS 2021-2023 (FoodData Central), fdc 2706176 and 2706177 · checked 2026-10-01
2. bolo-r7-01 · dataset
   FNDDS 25220410 Bologna (fdc 2706176): Energy 281 KCAL · Total lipid (fat) 23.77 G · Protein 10.34 G · Sodium, Na 1100 MG per 100 g · 1 slice, NFS 28 g · Guideline amount on regular sandwich 56 g · Guideline amount on large sandwich 84 g
   USDA FNDDS 2021-2023 (FoodData Central), food code 25220410, fdc 2706176 · checked 2026-10-01
3. bolo-r7-04 · laboratory analysis
   The mean residual NO2− content (in ppm) in decreasing order was: fresh (uncooked) pork sausage (26.9) > cooked poultry products (21.9) > cooked sausage products (21.7) > small diameter cooked sausage (10.2) > bacon (15.3) > ham (11.7) > specialty products (11.3) > large diameter cooked sausage (10.1) > dried smoked beef (9.5) > snack sausage (6.3) > jerky (3.7). ... Generally, NO2− progressively decreased to a very low content, whereas NO3− content was stable or increased slightly over the course of the storage period.
   Scientific Reports, 2025 · checked 2026-10-01
4. bolo-r7-05 · RCT
   A total of 113 healthy adults (18-50 years) were randomized, and 103 completed the study. ... FW genotoxicity increased significantly after MBD (+ 15.97%DNA damage; 95% CI 4.61 to 27.32; p = 0.006), with no significant within-group changes in MBD-T or PVD.
   Sci Rep, 2025 · checked 2026-10-01
5. bolo-r7-08 · meta-analysis of cohort studies
   Greater consumption of each of the three types of meat was associated with increased incidence of type 2 diabetes, with HRs of 1·10 (95% CI 1·06-1·15) per 100 g/day of unprocessed red meat (I2=61%), 1·15 (1·11-1·20) per 50 g/day of processed meat (I2=59%), and 1·08 (1·02-1·14) per 100 g/day of poultry (I2=68%).
   Lancet Diabetes Endocrinol, 2024 · checked 2026-10-01
6. bolo-r7-09 · meta-analysis of cohort studies
   Three studies (n = 381 291) were included in the random-effects model of measured body weight, resulting in a summary increase of 0.26 kg/y per 1 daily serving of processed meat (95% confidence interval [CI], 0.03-0.48; τ2: 0.03; I2: 92.95%).
   Nutr Rev, 2025 · checked 2026-10-01
7. bolo-r7-10 · agency guidance
   Deli meat, cold cuts, hot dogs, and fermented or dry sausages reheated to 165°F or until steaming hot
   US CDC, Preventing Listeria Infection · checked 2026-10-01
8. bolo-r7-06 · RCT
   Additionally, all three interventions (warning labels, tax, or combined warning labels + tax) led participants to select significantly fewer items containing processed meat.
   Int J Behav Nutr Phys Act, 2024 · checked 2026-10-01
9. bolo-r7-07 · randomized sensory trial
   The effect of information about fat content on expected and actual sensory and hedonic ratings of regular- and reduced-fat Bologna sausages was studied using 115 young men. ... After tasting, saltiness and fattiness of "Light Bologna" were rated lower while pleasantness and juiciness of the samples were not significantly different.
   Appetite, 1998 · checked 2026-10-01
10. bolo-r7-03 · dataset
    Bologna, beef | Fatty acids, total saturated 9.21 G | range 6.93-11.29 (median 9.41), samples 3 · Bologna, classic | Fatty acids, total saturated 7.398 G | range 3.82-10.78 (median 7.005), samples 6
    USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-10-01