(dissenting). I cannot agree that, when the Commonwealth rested its case, it had presented evidence sufficient to withstand the defendants’ motions brought under Mass.R.Crim.P. 25(a), 378 Mass. 896 (1979). Commonwealth v. Kelley, 370 Mass. 147, 149-150 (1976). Commonwealth v. Latimore, 378 Mass. 671, 677-678 (1979).
The charge set out in each of the identical indictments against the defendants bears repeating. Those indictments as amended charge that the defendants were of sufficient ability to provide their infant, Rita, “with sufficient food and drink for her sustenance and maintenance,” that they “did neglect and refuse so to do,” and that Rita, “being unable to provide sufficient food and drink for herself,” died. Assuming without deciding that these charges also embrace a failure and refusal to seek medical attention or an alternative food source for Rita, but see Commonwealth v. Grasso, 375 Mass. 138, 139-140 (1978), and Commonwealth v. Hobbs, 385 Mass. 863, 869-870 (1982), I would conclude that the evidence does not permit a finding beyond a reasonable doubt that Carol and Norman’s inaction in light of Rita’s condition created a “substantial and unjustifiable risk” of her death. Commonwealth v. Godin, 374 Mass. 120, 130 (1977).
The Commonwealth was required to prove far more than a mistake in judgment or a high degree of negligence. Wanton and reckless conduct “involves conscious creation of a *481substantial and unjustifiable risk.” Commonwealth v. Godin, 374 Mass. 130, citing the Model Penal Code § 2.02(c) (Proposed Official Draft 1962) (“A person acts recklessly with respect to a material element of an offense when he consciously disregards a substantial and unjustifiable risk that the material element exists or will result from his conduct. The risk must be of such a nature and degree that, considering the nature and purpose of the actor’s conduct and the circumstances known to him, its disregard involves a gross deviation from the standard of conduct that a law-abiding person would observe in the actor’s situation”). Cf. Restatement (Second) of Torts § 500, and comments a and b (1965).
To sustain its burden of proving beyond a reasonable doubt that Carol and Norman had acted wantonly and recklessly, the Commonwealth put in evidence the following: (1) Carol and Norman’s statements to the police; (2) Dr. Sturner’s opinion that if Carol had fed Rita in the manner described by her to Officer Mace,1 Rita would not have died from “an electrolyte imbalance due to malnutrition and dehydration as a result of starvation”; and (3) Rita’s physical appearance at the time of her death.
1. Carol and Norman’s Statements to the Police.
The jury, of course, would not be required to accept as true Carol’s and Norman’s statements to the police. However, a disbelief of their statements would not constitute substantive evidence to be evaluated in considering whether the Commonwealth had met its burden of proof. A disbelief of their statements provides neither affirmative evidence from which a jury could find that the contrary fact is true, see Commonwealth v. Marino, 343 Mass. 725, 728 (1962), *482nor an evidentiary basis from which a jury could find that Carol and Norman had a consciousness of guilt. A fact finder’s mere disbelief of a defendant’s consistent, exculpatory statements, either extra-judicial or testimonial, does not constitute evidence of a consciousness of guilt. Consciousness of guilt is shown by independent evidence of the defendant’s conduct which is inconsistent with his belief in his innocence. See United States v. McConney, 329 F.2d 467, 470 (2d Cir. 1964). See generally 1A, 2 Wigmore, Evidence § 173 and §§ 273-291 (3d ed. 1940). In the cases cited by the majority (Commonwealth v. Torrealba, 316 Mass. 24, 30 [1944]; Commonwealth v. Eppich, 342 Mass. 487, 491-492 [1961]; Commonwealth v. Swartz, 343 Mass. 709, 711-713 [1962]; Commonwealth v. Smith, 368 Mass. 126, 128-129 [1975]), the Commonwealth had presented independent evidence, which if accepted, would reasonably lead to the conclusion that the statements were false.
In my view, the only substantive value of their statements is found in their use as a factual basis for Dr. Sturner’s opinion.
2. Dr. Sturner’s Opinion.
I would hold that Dr. Sturner’s opinion that Rita would not have died of “malnutrition, dehydration, starvation” had Carol breast fed Rita six or seven times a day, thirty minutes each feeding, see note 1, supra, is entitled to no weight because he assumed critical facts not in evidence in reaching his opinion. See State Bd. of Retirement v. Contributory Retirement Appeal Bd., 342 Mass. 58, 65-66 (1961); Sweeney’s Case, 3 Mass. App. Ct. 284, 286 (1975). Cf. MacKay v. Ratner, 353 Mass. 563, 566-567 (1968).
Dr. Sturner assumed that Carol’s milk was of proper “quality,” a term he and counsel used to signify that Carol’s milk was of nutritional value. He also testified that the “quality” of a mother’s milk could have an effect on the nutritional needs of a breast-fed child. The jury could refuse to accept his testimony on this point but that refusal would not provide a basis for concluding that the “quality” of a mother’s milk does not have any effect on the child’s nutritional needs. Commonwealth v. Marino, 343 Mass, at *483728. Moreover, such a conclusion would be, in my opinion, beyond the scope of the ordinary experience of the fact finder. See Civitaresev. Gorney, 358 Mass. 652, 656 (1971); Commonwealth v. Harris, 1 Mass. App. Ct. 265, 268, S.C., 364 Mass. 236 (1973).
Proceeding on the assumption that Carol’s milk was of proper “quality,” Dr. Sturner next assumed that Rita was ingesting Carol’s milk for “full feedings” six or seven times a day, except for the week of her death. He also testified that it does not follow that a baby is ingesting milk simply because he or she is at the mother’s breast, that it is “a difficult situation,” that while some mothers are able to know whether their baby is ingesting, others do not, that it depends upon the individual mother, that he did not know Carol, that whether a baby was in fact ingesting would be an important factor in any consideration of malnutrition, and that a loss of even a small amount of fluid could be critical in the process of dehydration.
In my view there is a critical distinction between an opinion given in response to a hypothetical question from which important facts are omitted and an opinion based upon significant assumptions not in evidence. Where facts are omitted from the hypothetical question, it is the question which is flawed but capable of cure by opposing counsel on cross-examination of the expert. See Commonwealth v. Burke, 376 Mass. 539, 541 (1978) (“The omitted facts could have been presented to the witness in a hypothetical question asked in cross-examination”). Where, however, the opinion rests on facts not in evidence, the weakness is in the answer and not the question. And where those assumptions are important to the opinion, as Dr. Sturner conceded on cross-examination, the opinion is entitled to no weight. State Bd. of Retirement v. Contributory Retirement Appeal Bd., 342 Mass, at 65-66. Cf. Commonwealth v. Burke, 376 Mass, at 541. Compare Commonwealth v. Rembiszewski, 363 Mass. 311, 319-320 (1973). There is no adequate basis in the evidence for Dr. Sturner’s assumption that Carol’s *484milk was of proper “quality” or nutritional value.2 While the Commonwealth offered evidence to show that Rita could digest any food that she might ingest, there is no evidence to support the hypothesis put to Dr. Sturner that Rita had taken full feedings six or seven times a day except during the week of her death.3 Nor is there any basis for inferring that Carol knew whether Rita was ingesting during her feedings. The fact that Carol had breast-fed her three other children has no probative force without some evidence concerning the similarity, or lack of it, between any of those three experiences and the present one. Cf. Denton v. Park Hotel, Inc., 343 Mass. 524, 527-528 (1962); Elwell v. DelTorchio, 349 Mass. 766 (1965). Any inference that could be drawn from the fact that Carol used a breast pump and therefore knew that Rita was not taking milk is of no value. Carol stated to Officer Mace that she used a breast pump during the last week because Rita had cut down on her feedings. See note 1, supra. Moreover, Dr. Sturner’s opinion was based upon the fact that Rita had cut down.
Although Dr. Sturner testified only that Rita’s death was caused by an electrolyte imbalance due to malnutrition and dehydration as a result of starvation, the majority would allow the jury to conclude that “[d]eath by dehydration . . . would not have occurred even if the mother’s milk had no nutrients whatsoever, so long as she was feeding the child regularly.” I would hold that whether Rita would have died *485from an electrolyte imbalance due to malnutrition and dehydration as a result of starvation had she been fed milk containing no nutrients whatsoever six or seven times a day from June 29, 1980, to July 24, 1980, is a matter requiring expert medical testimony. Civitarese v. Gorney, 358 Mass, at 656. Commonwealth v. Harris, 1 Mass. App. Ct. at 268. There is nothing in Dr. Sturner’s opinion which supports the Commonwealth’s claim that Carol and Norman acted wantonly and recklessly.
3. Rita’s Physical Appearance.
The Commonwealth introduced evidence to show that Rita was discharged from the hospital within two days of her birth. During those two days, Rita lost nine ounces, and in the twenty-four days preceding her death, she lost thirteen ounces. She weighed approximately six pounds at the time of her death, and there was medical testimony as well as postdeath preautopsy photographs describing and depicting her physical appearance.
Rita’s physical appearance would be probative of whether Carol and Norman knew or should have known that Rita was not receiving sufficient food. Moreover, the Commonwealth’s position on appeal and the majority’s statement that the evidence was sufficient to allow a jury to conclude that Carol and Norman “neglected and refused properly to feed and care for” Rita (emphasis added) prevent limiting consideration of Rita’s appearance to the question whether Rita died because Carol and Norman failed and refused to provide her with sufficient amounts of Carol’s milk. There is no medical testimony concerning whether a breast-feeding mother faced with feeding problems may simply provide her infant with an alternative food source without first obtaining medical advice as to what the infant can and should be fed. Additionally, the Commonwealth made no reference at trial, nor does it claim in its brief before us, that Carol and Norman merely could have purchased milk and fed it to Rita. Rather, the Commonwealth states “that they both knew . . . that the child was not being properly fed and still did nothing about it.” At oral argument, the Com*486monwealth became more specific concerning the phrase “did nothing about it” and argued that Carol and Norman’s failure to seek medical attention for Rita in light of her physical appearance constituted wanton and reckless conduct. Accordingly, if the Commonwealth has a theory of criminal liability other than that Carol and Norman failed to provide Rita with sufficient amounts of Carol’s milk, I would limit that theory to a failure to seek medical attention for Rita in light of her appearance.4
The Commonwealth offered no evidence to show that Carol’s milk was of nutritional value or that, even if it wasn’t, Rita would not have died of an electrolyte imbalance caused by malnutrition or dehydration if she had been fed regularly. While it seems obvious that Rita was able to, and in fact did, ingest some amounts of her mother’s milk during the twenty-six days of her life, it does not follow, as Dr. Sturner testified in respect to breast-feeding infants in general, that Rita was able and willing to ingest sufficient food had it been provided for her. Rita died before the date of her first scheduled examination by a pediatrician. Carol told Officer Mace that Rita cut down on her feedings during the last week and that she, Carol, thought Rita had been getting heavier. While Carol’s statements need not be accepted, there is no evidence to show that Rita’s weight loss was a process of steady deterioration rather than a sudden event over a short time span. Dr. Sturner testified that a loss of even a small amount of fluid could be critical in the process of dehydration. There is no evidence whether Rita’s condition and appearance at the time of her death was consistent with a process of deterioration and inconsistent with a rapid weight loss. In light of this state of the evidence, I view Rita’s physical appearance at the time of her death as an in*487sufficient basis for an inference either that Carol and Norman knew that they were not giving Rita a proper amount of her mother’s milk or that Carol and Norman knew that Rita was in need of medical attention. See Commonwealth v. Rosenberg, 379 Mass. 334, 339-344 (1979). Compare Commonwealth v. Godin, 374 Mass, at 129-130; Commonwealth v. Gallison, 383 Mass. 659, 666 (1981). See also State v. Rupp, 586 P.2d 1302 (Ariz. App. 1978); Eaglen v. State, 249 Ind. 144 (1967); Ahearn v. State, 588 S.W.Sd 327 (Tex. Crim. App. 1979). See generally Annot., Homicide by Withholding Necessities, 61 A.L.R.Sd 1207, 1216-1224 (1975).
I would conclude that the Commonwealth failed to prove beyond a reasonable doubt that Carol and Norman were guilty of wanton and reckless conduct which resulted in Rita’s death. I would reverse the defendants’ convictions and remand the matter to the Superior Court for the entry of required findings of not guilty.
Carol told Officer Mace that she fed the baby six to seven times a day, fifteen minutes on each of her breasts at each feeding, and that when the baby cut down on her feedings during the last week, she would use a breast pump, although not that often, and bottle feed Rita with that milk later. On one occasion, Carol was able to pump eight ounces of milk from her breasts, but usually the amount was “three to three and half ounces of both breasts combined.”
On the afternoon of Rita’s death, Carol was given Miranda warnings and questioned by Officer Mace, whose inquiries had been prepared for him by Dr. Sturner. Carol was not questioned about her own physical condition, she was not asked if she would take a physical examination, nor was she requested to make a sample of her milk available for analysis. Dr. Martino testified that Carol’s prenatal examinations indicated that prior to delivery she had no particular problems. Her urine was tested for protein and glucose. He regarded Carol’s pregnancy as one “without any complications.” Carol’s and Norman’s statements to the police contain no information concerning the “quality” of Carol’s milk.
Dr. Sturner testified that in conducting the autopsy, he found no organic or physiological inability on the part of Rita to absorb food, and he found no congenital abnormality in Rita’s face and mouth area.
Because I would conclude that the evidence is insufficient to support convictions based on a failure to seek medical attention, it is unnecessary to consider whether that failure constitutes a material variance from the charge set out in the indictments or, if not, whether the defendants suffered any prejudice. See Commonwealth v. Grasso, 375 Mass, at 139-140; Commonwealth v. Hobbs, 385 Mass, at 869-870.