UNITED STATES COURT OF APPEALS FOR VETERANS CLAIMS 

No. 18-0495 

ELIZABETH M. WALSH, APPELLANT, 

V. 

ROBERT L. WILKIE, 

SECRETARY OF VETERANS AFFAIRS, APPELLEE. 

On Appeal from the Board of Veterans' Appeals 

(Decided February 24, 2020) 

Kaitlyn C. Degnan, of Providence, Rhode Island, was on the brief for the appellant. 

Richard J. Hipolit, Acting General Counsel; Mary Ann Flynn, Chief Counsel; Christopher 

W. Wallace, Deputy Chief Counsel; and Ronen Morris, all of Washington, D.C., were on the brief 

for the appellee.

Before BARTLEY, Chief Judge, and PIETSCH and TOTH, Judges. 

TOTH, Judge: A veteran is entitled to disability compensation when a service-connected 

disability causes or aggravates a non-service-connected disability. In a precedent opinion, the VA 

General Counsel (G.C.) determined that obesity, although itself not a disability for which 

compensation may be awarded, can constitute an "intermediate step" in demonstrating service 

connection on a secondary basis for another condition. 

Elizabeth M. Walsh appeals the Board's denial of service connection for hypertension and 

sleep apnea. The question raised in this case is whether this "intermediate step" is limited to 

situations in which a service-connected disability causes obesity—the hypothetical situation used 

by the G.C. opinion—or also embraces situations in which a service-connected disability 

aggravates obesity. We conclude that, whatever the phrasing of the G.C. opinion, there is no legal 

basis to recognize a causal relationship but not an aggravating one in these circumstances. Because 

the December 2017 Board decision relied on a medical opinion that did not adequately address 

whether secondary service connection for hypertension and sleep apnea was warranted based on a 

theory that the veteran's obesity was aggravated by service-connected conditions, we vacate and 

remand for further proceedings. 
2 

 Ms. Walsh served on active duty for training in the Army Reserves from January to June 

1978. During this period, she fell and injured both knees. In September 1978, she was granted 

service connection for bilateral chondromalacia, a breakdown of cartilage in the knee joint that 

causes pain when bones rub together.1 In the years that followed, the bilateral knee ratings were 

increased and service connection was also granted for, among other things, arthritis in both hips 

and a low back disability. Per the veteran, because of pain and the soporific effects of prescribed 

pain medication, these conditions severely limited her mobility. 

 In June 2009, Ms. Walsh sought disability compensation for hypertension and a "sleeping 

condition" as secondary to her service-connected knee, hip, and back conditions. R. at 3158. The 

VA regional office denied the claims and she appealed. While appellate litigation proceeded, the 

veteran underwent a VA sleep study, which diagnosed mild obstructive sleep apnea. In an April 

2014 report, a VA examiner opined that Ms. Walsh's sleep apnea was "likely due to her 

documented weight gain/obesity" and that the onset of hypertension coincided with "increased 

weight/obesity." R. at 1694-95. But the examiner opined that neither sleep apnea nor hypertension 

was caused or aggravated by service-connected knee, hip, or back conditions. VA continued to 

deny the claims. 

 The Board remanded the claims in May 2016. Noting the veteran's reports that she was a 

"very athletic and active adult" before her service-connected disabilities began and the most recent 

examiner's attribution of sleep apnea and hypertension to obesity, the Board sent the serviceconnection claims back for a new etiology opinion. Specifically, it asked for an examiner to 

address whether it was at least as likely as not that Ms. Walsh's obesity, which was "noted as the 

cause" of her hypertension and sleep apnea, was either caused or aggravated by service-connected 

disabilities. R. at 676-77. 

 While VA was attempting to obtain such an opinion, G.C. Precedent Opinion 1-2017 was 

issued, which discussed the potential for disability compensation based on obesity. As a 

preliminary matter, the opinion generally determined that obesity itself was ineligible for service 

connection on direct or secondary bases because it did not qualify as a disease or injury. G.C. Prec. 

Op. 1-2017, at 2-7 (Jan. 6, 2017).2

 (We subsequently held that we lacked jurisdiction to consider 

 1 Knee Pain (Chondromalacia Patella), CLEVELAND CLINIC, https://my.clevelandclinic.org/health/diseases/

15607-knee-pain-chondromalacia-patella. 

2

 Available at https://www.va.gov/OGC/docs/2017/VAOPGCPREC1-2017.pdf. The opinion recognized the 
3 

a challenge to this determination because it would entail impermissible judicial review of the rating 

schedule's content. Marcelino v. Shulkin, 29 Vet.App. 155, 157-58 (2018) (citing 38 U.S.C. § 

7252(b)).) The G.C. opinion nevertheless reasoned that "[o]besity may be an 'intermediate step' 

between a service-connected disability and a current disability that may be service connected on a 

secondary basis under 38 C.F.R. § 3.310(a)." G.C. Prec. Op. 1-2017, at 2-3. Somewhat presciently 

for our purposes, the opinion used the example of a veteran seeking service connection for 

hypertension on the theory that the "veteran's service-connected back disability causes obesity due 

to lack of exercise, which leads to hypertension." Id. at 9. 

Under 38 C.F.R. § 3.310(a), disability which is proximately due to or the result of 

a service-connected disease or injury is service connected. "Proximate cause" is 

defined as a "cause that directly produces an event and without which the event 

would not have occurred." When there are potentially multiple causes of a harm, 

an action is considered to be a proximate cause of the harm if it is a substantial 

factor in bringing about the harm and the harm would not have occurred but for the 

action. 

 

A determination of proximate cause is basically one of fact, for determination by 

adjudication personnel. With regard to the hypothetical presented in the previous 

paragraph, adjudicators would have to resolve the following issues: (1) whether the 

service-connected back disability caused the veteran to become obese; (2) if so, 

whether the obesity as a result of the service-connected disability was a substantial 

factor in causing hypertension; and (3) whether the hypertension would not have 

occurred but for obesity caused by the service-connected back disability. If these 

questions are answered in the affirmative, the hypertension may be service 

connected on a secondary basis. 

Id. at 9-10 (citations and some quotation marks omitted). Thus, the first step asks about the 

connection between a service-connected disability and obesity, while the second and third steps 

ask about the connection (proximate and but-for causation) between obesity and the disability for 

which secondary service connection is sought. 

 VA eventually obtained a medical opinion, but because it did not align with the framework 

set out in the G.C. opinion, VA sought another one. In its opinion request, VA asked (under the 

"at least as likely as not" standard): (1) whether the veteran's service-connected disabilities, 

including medications prescribed to treat them, "caused" the veteran to gain weight or become 

 

potential to award extraschedular compensation in a particular case where "obesity resulting from a service-connected 

disease or injury is found to produce impairment beyond that contemplated by the applicable provisions of VA's rating 

schedule" for the service-connected disability. G.C. Prec. Op. 1-2017, at 1. 
4 

obese; (2) if so, whether the weight gain or obesity resulting from the service-connected disability 

was a substantial factor in "causing" hypertension or sleep apnea; and (3) again, if so, whether 

hypertension or sleep apnea would not have occurred but for weight gain or obesity "caused" by 

the service-connected disability. R. at 21. If the medical expert answered "yes" to these three 

questions with respect to one of the conditions (hypertension or sleep apnea) but not the other, VA 

asked the expert to further address whether the other condition was "proximately due to" or 

"aggravated (permanently worsened beyond the natural progress of the disease)" by the nowservice-connected condition or its medications.3 Id. 

 The requested opinion was provided in July 2017 by a physician who was on the staff of 

the local VA medical center and an assistant professor of medicine at a nearby university. After 

fully listing all service-connected disabilities, she said with respect to the first question that she 

couldn't state "with greater than 50% probability" that such disabilities "contributed to obesity." 

R. at 17. As relevant here, she observed that 

there is a complex interaction between energy expenditure and caloric intake. 

Obesity develops over a period of time. Physical activity, caloric intake, genetic 

factors, microbiome are all important factors. A recent longitudinal study that 

evaluated the cause of obesity noted that physical activity decreased the probability 

of being overweight by 4.3-6.5% based on a linear model but did not support the 

causal link between Leisure Time Physical activity and [being] overweight. 

Id. Referencing the "proximate cause" language of G.C. Opinion 1-2017, the physician said she 

couldn't state, based on the current evidence and medical literature, "that there is a cause-effect 

relationship between arthritis of the back or of the knee and obesity." Id. As for the second 

question, the physician advised that obesity is "a significant factor that causes obstructive sleep 

apnea [and] hypertension." R. at 18. Last, the physician opined that it was as likely as not that sleep 

apnea and hypertension "would not have occurred but for" obesity. R. at 19. (Given her responses 

to the first three questions, the physician did not answer the remaining ones.) She concluded that, 

although there is evidence that obesity is "related to hypertension and sleep apnea," "there is no 

clear-cut evidence that decreased physical activity secondary to arthritis is causally related to 

[o]besity." Id. 

 3

 The Court recently clarified in Ward v. Wilkie, 31 Vet.App. 233, 237-38 (2019), that the proper standard in 

an aggravation inquiry is not whether there was "permanent worsening" but rather "any increase" in disability. 
5 

 The Board relied on the physician's opinion for the conclusion that "obesity cannot be 

attributed to [the veteran's] service-connected disabilities" and denied service connection for 

hypertension and sleep apnea on a secondary basis. R. at 7. The medical opinion was adequate and 

probative, the Board found, because it was "unequivocally stated" and "supported by the evidence 

of record and a detailed rationale." Id. This appeal followed. 

 Ms. Walsh makes several arguments on appeal. Among these, she contends that the 

analysis set out in G.C. Opinion 1-2017 requires a determination of whether obesity was caused 

or aggravated by a service-connected disability and that the 2017 VA medical opinion fails to 

address aggravation. Appellant's Br. at 9-11. The Secretary does not directly address this argument, 

stating instead that the 2017 medical opinion "provided the Board with the information it needed 

to make a fully informed decision" and that Ms. Walsh "does not challenge the propriety of the 

General Counsel opinion or show how the [medical] expert deviated from the relevant and required 

analysis." Secretary's Br. at 8. G.C. Opinion 1-2017 does not mention the concept of aggravation 

in the portion that discusses obesity as an "intermediate step" and references only subsection (a) 

of 38 C.F.R. § 3.310. Nevertheless, the principles contained in § 3.310 make any distinction in 

G.C. Opinion 1-2017 between causation and aggravation legally untenable. 

As an initial matter, we note that G.C. precedent opinions are issued by VA's chief legal 

officer and are binding on the Board. 38 U.S.C. § 7104(c). They are not, however, binding on the 

Court. Molitor v. Shulkin, 28 Vet.App. 397, 408 (2017). Instead, because such opinions lack the 

formalities of notice-and-comment rulemaking, the Court defers to them in accordance with their 

"'power to persuade.'" Wanless v. Shinseki, 618 F.3d 1333, 1338 (Fed. Cir. 2010) (quoting 

Skidmore v. Swift & Co., 323 U.S. 134, 140 (1944)). 

To properly analyze Ms. Walsh's arguments with respect to G.C. Opinion 1-2017, we must 

start with the language of the regulation governing secondary service connection. Section 3.310 

first provides that "disability which is proximately due to or the result of a service-connected 

disease or injury shall be service connected." 38 C.F.R. § 3.310(a) (2019). This describes a causal 

relationship. See MacPhee v. Nicholson, 459 F.3d 1323, 1327 (Fed. Cir. 2006). In the next 

subsection, the regulation specifies that "[a]ny increase in severity of a nonservice-connected 

disease or injury that is proximately due to or the result of a service-connected disease or injury, 

and not due to the natural progress of the nonservice-connected disease, will be service connected." 

38 C.F.R. § 3.310(b). This, as the provision itself recognizes, describes an aggravating relationship. 
6 

See id. The operative language in these provisions is essentially identical. Both discuss something 

that "is proximately due to or the result of a service-connected disease or injury" and advise that 

this "shall [or will] be service connected." Nothing in this language justifies a distinction between 

causation and aggravation in the first step of the analysis in G.C. Opinion 1-2017. 

 Aside from (b)'s "natural progress" clause, the only difference between the two subsections 

is the subject of the operative language: in (a) it is a "disability," whereas in (b) it is an "increase 

in severity of a nonservice-connected disease or injury." But, for purposes of the present inquiry, 

these terms are conceptually synonymous. Our decision in Allen v. Brown, 7 Vet.App. 439, 448 

(1995) (en banc), makes clear that "when aggravation of a veteran's non-service-connected 

condition is proximately due to or the result of a service-connected condition, such veteran shall 

be compensated for the degree of disability (but only that degree) over and above the degree of 

disability existing prior to the aggravation."4 In other words, aggravation is just causation of an 

increase in disability—i.e., a discrete portion of disability—rather than of the whole disability 

itself. Thus, Allen held that the term "disability" includes "any additional impairment of earning 

capacity resulting from an already service-connected condition." 7 Vet.App. at 448. The remainder 

of subsection (b) bears this out. It instructs VA adjudicators to "determine the baseline and current 

levels of severity under the Schedule for Rating Disabilities . . . and determine the extent of 

aggravation by deducting the baseline level of severity, as well as any increase in severity due to 

the natural progress of the disease, from the current level." 38 C.F.R. § 3.310(b). Therefore, the 

fact that subsection (b) uses the phrase "increase in severity of a nonservice-connected disease or 

injury" rather than "disability," as appears in subsection (a), is of no legal moment. 

 In short, there is no permissible basis in the relevant regulation for concluding that obesity 

may be an "intermediate step" in a secondary-service-connection analysis when service-connected 

disability causes it, but not when service-connected disability aggravates it. So, where does that 

leave G.C. Opinion 1-2017? The Secretary's brief is carefully agnostic as to whether G.C. Opinion 

1-2017 takes a position on the aggravation-of-obesity issue and, if so, whether that position is 

 4 Allen's conclusion was based on a reading of the relevant statutes. Before Allen, "VA paid compensation 

for a disability on a secondary basis only if the secondary condition was entirely caused by a service-connected 

disability." Claims Based on Aggravation of a Nonservice-Connected Disability, 62 Fed. Reg. 30,547, 30,547 (June 

4, 1997) (proposed rule) (emphasis added). 
7 

consistent with § 3.310. Importantly, the Board may not rely on a G.C. opinion that is inconsistent 

with a valid regulation. See, e.g., Franklin v. Brown, 5 Vet.App. 190, 192-93 (1993). 

 Based on our review of G.C. Opinion 1-2017, however, we discern no necessary 

inconsistency between it and § 3.310 on this issue.5 It's true that the portion of the opinion 

addressing obesity as an "intermediate step" in the secondary-service-connection context never 

mentions aggravation. But we do not read that omission as an affirmative position that aggravation 

is a legally irrelevant consideration. G.C. Opinion 1-2017 provides guidance on how to analyze 

obesity as an "intermediate step" using a hypothetical "example" in which a "service-connected 

back disability causes obesity due to lack of exercise, which leads to hypertension." G.C. Prec. Op. 

1-2017, at 9. The causal relationship between the service-connected condition and obesity 

(causation) is no more integral to the opinion's analytic framework than is the identity of the 

service-connected condition (a back disability). This can be seen by substituting aggravation for 

causation in the hypothetical as follows: (1) whether the service-connected back disability 

aggravated the veteran's obesity; (2) if so, whether the aggravation of obesity as a result of serviceconnected disability was a substantial factor in causing hypertension; and (3) whether the 

hypertension would have occurred but for obesity aggravated by the service-connected back 

disability. Cf. id. Such an inquiry is consistent with both the legal principles of § 3.310(b) and the 

analytic principles sketched out by the General Counsel. 

 In other words, properly construed, G.C. Opinion 1-2017 does not purport to prohibit 

inquiry into whether a service-connected disability aggravates a veteran's obesity. And for good 

reason, as this would contradict VA's aggravation regulation. So, to be clear: Despite the G.C. 

opinion's silence regarding aggravation, the Board, in accordance with § 3.310(b), must consider 

aggravation in this context when the theory is explicitly raised by the veteran or reasonably raised 

by the record. 

 With this legal matter resolved, we turn to the Board decision here. We conclude that the 

Board clearly erred in finding the 2017 VA medical opinion adequate. Among other requirements, 

to be adequate, a VA medical opinion must address the medical question at issue in enough detail 

that the Board can make a fully informed evaluation of the claim. Atencio v. O'Rourke, 30 Vet.App. 

74, 89 (2018). Here, the Board found in its May 2016 remand that the evidence of record 

 5

 Ms. Walsh's appeal does not implicate, and we have no occasion to address, any other aspect of G.C. 

Opinion 1-2017's analysis. 
8 

necessitated a medical opinion as to whether service-connected disability caused or aggravated 

her obesity. R. at 676-77. But the 2017 opinion on which it relied is silent on the question of 

aggravation of obesity. To the extent the Board thought, after issuance of G.C. Opinion 1-2017, 

that a medical opinion—on whether service-connected disability aggravated Ms. Walsh's 

obesity—was no longer legally relevant, the present opinion dispels that misconception. But the 

fact remains that the physician was not asked for a medical opinion on the question of aggravation 

and her report provides no information on which the Board can rely to adjudicate that theory of 

service connection. Thus, the Board clearly erred in finding the 2017 VA opinion adequate to 

decide these claims. We remand for the Board to obtain a new medical opinion that provides 

sufficient information on relevant medical issues—such as whether service-connected knee, hip, 

and back disabilities caused or aggravated Ms. Walsh's obesity—to allow it to make a "fully 

informed" decision on the hypertension and sleep apnea claims. Atencio, 30 Vet.App. at 89. 

 Finally, we note that Ms. Walsh makes several other arguments, such as that the 2017 VA 

medical opinion was inadequate because the physician used improperly high standards when 

resolving medical questions and that the Board clearly erred in finding that she did not have a 

current sleep apnea disability. (Regarding this last assertion, she points to a February 2013 VA 

diagnostic polysomnography report diagnosing mild obstructive sleep apnea and prescribing 

continuous positive airway pressure therapy. R. at 771-72.) Given our determination that remand 

is already warranted, we need not resolve those arguments now, nor do we think they are 

appropriate for resolution in a precedential decision. We trust that the Board, as part of its 

obligation on remand to provide a critical reassessment of the claims, see Roberts v. McDonald, 

27 Vet.App. 108, 113-14 (2014), will duly consider these arguments and all relevant legal and 

factual disputes. 

 The December 8, 2017, Board decision is VACATED and the claims are REMANDED for 

further proceedings consistent with this opinion.