Microbial growth consists of the conversion of nutrients from the environment into biomassand small energy cofactors (ATP, NADH, NADPH, ...) driving biomass synthesis forward. Twomacroscopic criteria for characterizing microbial growth are growth rate and growth yield. Theformer refers to the rate of conversion of substrate into biomass, and the latter to the efficiencyof the process, that is, the fraction of substrate taken up by the cells that is converted intobiomass.Different strains of a microorganism growing in the same environment display a wide varietyof growth rates and growth yields. We developed a coarse-grained model, coupling the fluxesof carbon and energy, to test the hypothesis that different resource allocation strategies, cor-responding to different compositions of the proteome, can account for the observed rate-yieldvariability. The model predictions were verified by means of a database of hundreds of pub-lished rate-yield and uptake-secretion phenotypes of Escherichia coli strains grown in standardlaboratory conditions. We found a very good quantitative agreement between the range of pre-dicted and observed growth rates, growth yields, and glucose uptake and acetate secretion rates.These results support the hypothesis that resource allocation is a major explanatory factor ofthe observed variability of growth rates and growth yields across different bacterial strains. Aninteresting prediction of our model, supported by the experimental data, is that high growthrates are not necessarily accompanied by low growth yields. The resource allocation strategiesenabling high-rate, high-yield growth of E. coli lead to a higher saturation of enzymes andribosomes, and thus to a more efficient utilization of proteomic resources.