## Facts

- Bruce A. Tanberg, a motel guest, fell while exiting a whirlpool bathtub in his room and injured his back.
- Tanberg sued the motel operator, Ackerman Investment Co. (doing business as Best Western Starlite Village), alleging negligent conditions related to the bathtub and bathroom.
- At the time of the accident, Tanberg was 5'11" and weighed 309 pounds.
- Treating physicians repeatedly advised Tanberg to lose weight as part of treatment to reduce back pain and decrease stress on his spine.
- Evidence supported that Tanberg did not follow the recommended diet and weight-loss regimen to the extent advised.

## Issues

1. Whether a plaintiff’s unreasonable post-injury failure to follow medical advice to lose weight, given to reduce pain and prevent further problems, may be treated as “fault” (failure to mitigate damages) under Iowa Code ch. 668.
2. Whether treating such post-injury conduct as comparative fault conflicts with the “eggshell plaintiff” rule protecting plaintiffs from fault based on preexisting conditions.

## Decision

- The Iowa Supreme Court vacated the court of appeals decision and affirmed the district court’s judgment for the defendant.
- The court held that Iowa Code § 668.1(1) expressly includes within “fault” an unreasonable failure to mitigate damages.
- The district court properly instructed the jury that Tanberg’s unreasonable failure to follow reasonable medical advice, including advice to lose weight, could be considered in allocating comparative fault.
- The “eggshell plaintiff” rule did not bar consideration of Tanberg’s post-injury conduct because the rule concerns preexisting conditions, not unreasonable failures to mitigate after injury.

## Legal Principles

- Under Iowa Code ch. 668, “fault” includes negligence and an “unreasonable failure to avoid an injury or to mitigate damages.”
- A plaintiff’s preexisting condition (such as obesity) is not itself comparative fault; a defendant remains liable for harm proximately caused even if the plaintiff is more susceptible to injury.
- Post-injury conduct may constitute comparative fault when there is evidence that (1) medical advice was reasonable and aimed at mitigating damages and (2) the plaintiff unreasonably failed to follow it.
- Mitigation-based fault concerns the extent of damages after the tort, not liability for the initial injury-producing event.

## Conclusion

The court held that Iowa’s comparative fault statute permits the jury to treat a plaintiff’s unreasonable, post-injury failure to follow reasonable medical advice aimed at reducing harm—including advice to lose weight—as “fault” for purposes of allocating responsibility, without violating the eggshell plaintiff rule.


Tanberg v. Ackerman Inv. Co., 473 N.W.2d 193 (Iowa 1991)