Ubugari bukozwe mu ifu y’imyumbati ni ifunguro rikungahaye cyane ku ntungamubiri zitanga ingufu, cyane cyane ibinyamasukari byitwa starch (ibinyamasukari by’ingenzi bitanga ingufu).
Imyumbati ubwayo igizwe ahanini n’ibinyamasukari (carbohydrates), mu gihe poroteyine n’amavuta birimo ari bike. Ibi bituma ubugari bw’imyumbati bushobora kuba isoko y’ingufu umubiri ukoresha mu bikorwa bya buri munsi.
Ibinyamafufu (carbohydrates) ni byo umubiri ukoresha nk’isoko ikomeye y’ingufu.
Ishami ry’Umuryango w’Abibumbye ryita ku Buzima (OMS) rivuga ko ku bantu benshi ibinyamafufu bigomba kuba igice cy’ingenzi cy’indyo, ariko rikagaragaza ko ubwiza bwabyo n’aho biva ari ingenzi ku buzima.
Ibi bivuze ko ubugari bw’imyumbati bushobora gufasha cyane cyane mu gutanga imbaraga, ariko ubwabwo ntibuhagije kugira ngo umubiri ubone intungamubiri zose ukenera.
Ubushakashatsi ku ifu n’umushonge w’imyumbati bwerekana ko hari ubwoko bw’imyumbati bushobora kugira starch igogorwa buhoro (resistant starch), ni ukuvuga ubwoko bw’ibinyamafufu budasemburwa vuba mu mara mato.
Ubushakashatsi bw’isuzuma ku ifu y’imyumbati bwerekanye ko ingano y’iyi starch igogorwa buhoro ishobora gutandukana cyane bitewe n’ubwoko bw’imyumbati ndetse n’uburyo ifu yatunganyijwe.
Starch igogorwa buhoro ifatwa nk’ubwoko bwa fibre (utunyangingo dufasha igogora ry’ibiribwa), kandi ubushakashatsi buracyakomeza gusuzuma uruhare rwayo ku buzima bw’umubiri.
Ku rundi ruhande, ntibikwiye kuvugwa ko ubugari bw’imyumbati ari isoko ikomeye ya fibre muri rusange. Ingano ya fibre ishobora guterwa n’uko ifu yakozwe ndetse n’uburyo imyumbati yatunganyijwe.
OMS isaba ko abantu bakuru n’abana barengeje imyaka 10 babona nibura garama 25 za fibre ku munsi, cyane cyane binyuze mu ndyo irimo imboga, imbuto, ibinyampeke bitatunganyijwe cyane n’ibinyamisogwe.
Ikindi kintu cy’ingenzi ni uko imyumbati ifite poroteyine nke.
Ishami ry'Umuryango w’Abibumbye wita ku Biribwa n’Ubuhinzi (FAO) ugaragaza ko igice kiribwa cy’umwumbati kigizwe ahanini n’ibinyamasukari, mu gihe poroteyine iba hafi ya 1–2%.
Ibi bivuze ko umuntu urya ubugari bw’imyumbati kenshi adakwiye kubufata nk’isoko nyamukuru ya poroteyine.
Ni yo mpamvu ubugari bw’imyumbati bushobora kurushaho kugira agaciro mu mirire iyo buririwe hamwe n’ibindi biribwa bikungahaye kuri poroteyine, nk’ibishyimbo, amashaza, soya, amagi, amafi cyangwa inyama, ndetse n’imboga n’imbuto.
OMS ishimangira ko indyo nziza igomba kuba itandukanye kandi ikagira uburinganire hagati y’ibinyamasukari, poroteyine, amavuta, vitamine n’imyunyu ngugu.
Hari kandi ikintu cyihariye ku myumbati kitagomba kwirengagizwa. Imyumbati irimo ibintu byitwa cyanogenic glycosides (ibinyabutabire bishobora kurekura cyanide), cyane cyane linamarin na lotaustralin, bishobora kurekura hydrogen cyanide (cyanide ishobora kwangiza umubiri).
Ni yo mpamvu imyumbati igomba gutunganywa neza mbere yo kuribwa. FAO igaragaza ko uburyo bwo kuyitunganya burimo kuyisya, kuyishira mu mazi, kuyisembura, kuyikamura no kuyumisha bishobora kugabanya cyane cyanide.
Bityo, iyo ifu y’imyumbati yakoreshejwe mu gukora ubugari yatunganyijwe neza kandi ikaba yujuje ibisabwa, ikibazo cya cyanide ntikigomba gufatwa nk’impamvu yo kwirinda ubugari bw’imyumbati muri rusange.
Icy’ingenzi ni uburyo imyumbati yatunganyijwemo.
Muri rusange, ubushakashatsi butuma tuvuga ko inyungu nyamukuru y’ubugari bw’imyumbati ari ugutanga ingufu, bitewe n’ubwinshi bw’ibinyamasukari burimo.
Hari kandi ubushakashatsi kuri starch igogorwa buhoro iri mu ifu y’imyumbati, ariko ingano yayo n’akamaro kayo bishobora guhinduka bitewe n’ubwoko bw’imyumbati n’uburyo yatunganyijwe.
Ntabwo rero ari byo kuvuga ko ubugari bw’imyumbati ari “umuti” w’indwara runaka.
Icy’ingenzi ku muntu urya ubugari bw’imyumbati ni uko agomba kumenya ko bushobora kuba igice cy’indyo nziza, ariko bukaba bugomba kujyana n’ibindi biribwa kugira ngo umubiri ubone poroteyine, fibre, vitamine n’imyunyu ngugu bihagije.