Diamond bonded constructions include a diamond body comprising intercrystalline bonded diamond and interstitial regions. The body has a working surface and an interface surface, and may be joined to a metallic substrate. The body has a gradient diamond volume content greater about 1.5 percent, wherein the diamond content at the interface surface is less than 94 percent, and increases moving toward the working surface. The body may include a region that is substantially free of a catalyst material otherwise disposed within the body and present in a gradient amount. An additional material may be included within the body and be present in a changing amount. The body may be formed by high-pressure HPHT processing, e.g., from 6,200 MPa to 10,000 MPa, to produce a sintered body having a characteristic diamond volume fraction v. average grain size relationship distinguishable from that of diamond bonded constructions form by conventional-pressure HPHT processing.