A gastric balloon system for treatment of obesity in a patient comprising: a transabdominal gastric cannula for gastric balloon insertion or manipulation in a stomach lumen comprising: an outer end; an inner end; a central portion having an outer-facing surface that extends between said inner end and said outer end and an inner-facing surface that defines a lumen; an internal anchor connected to said inner end and having a surface shape configured to secure the system against an interior surface of a gastric wall; an external anchor removably and translationally connected to said cannula outer-facing surface and having a surface shape configured to secure said system against a skin surface. a size-varying gastric balloon configured for delivery to a stomach lumen through the transabdominal gastric cannula or endoscopically, said size-varying gastric balloon comprising: a gastric balloon surface; an internal volume defined by said gastric balloon surface; a gastric balloon anchor connected to said gastric balloon surface configured to reliably position and anchor said size-varying gastric balloon in a gastric environment; a fluid conduit that traverses said lumen of the transabdominal gastric cannula, the fluid conduit having a first fluid end and a second fluid end: wherein said first fluid end is connected to said size-varying gastric balloon and in fluid communication with said internal volume and said second fluid end is positioned external to the size-varying gastric balloon internal volume; wherein said fluid conduit is configured to introduce a fluid to said internal volume to increase said internal volume to a deployed internal volume and provide a gastric balloon deployed configuration; said size-varying gastric balloon having an annulus in said deployed configuration configured to align in the stomach to pass food and liquid in a direction from an esophageal exit toward a pyloric sphincter. a transabdominal gastric cannula for gastric balloon insertion or manipulation in a stomach lumen comprising: an outer end; an inner end; a central portion having an outer-facing surface that extends between said inner end and said outer end and an inner-facing surface that defines a lumen; an outer end; an inner end; a central portion having an outer-facing surface that extends between said inner end and said outer end and an inner-facing surface that defines a lumen; an internal anchor connected to said inner end and having a surface shape configured to secure the system against an interior surface of a gastric wall; an external anchor removably and translationally connected to said cannula outer-facing surface and having a surface shape configured to secure said system against a skin surface. a size-varying gastric balloon configured for delivery to a stomach lumen through the transabdominal gastric cannula or endoscopically, said size-varying gastric balloon comprising: a gastric balloon surface; an internal volume defined by said gastric balloon surface; a gastric balloon anchor connected to said gastric balloon surface configured to reliably position and anchor said size-varying gastric balloon in a gastric environment; a gastric balloon surface; an internal volume defined by said gastric balloon surface; a gastric balloon anchor connected to said gastric balloon surface configured to reliably position and anchor said size-varying gastric balloon in a gastric environment; a fluid conduit that traverses said lumen of the transabdominal gastric cannula, the fluid conduit having a first fluid end and a second fluid end: wherein said first fluid end is connected to said size-varying gastric balloon and in fluid communication with said internal volume and said second fluid end is positioned external to the size-varying gastric balloon internal volume; wherein said fluid conduit is configured to introduce a fluid to said internal volume to increase said internal volume to a deployed internal volume and provide a gastric balloon deployed configuration; said size-varying gastric balloon having an annulus in said deployed configuration configured to align in the stomach to pass food and liquid in a direction from an esophageal exit toward a pyloric sphincter. wherein said first fluid end is connected to said size-varying gastric balloon and in fluid communication with said internal volume and said second fluid end is positioned external to the size-varying gastric balloon internal volume; wherein said fluid conduit is configured to introduce a fluid to said internal volume to increase said internal volume to a deployed internal volume and provide a gastric balloon deployed configuration; said size-varying gastric balloon having an annulus in said deployed configuration configured to align in the stomach to pass food and liquid in a direction from an esophageal exit toward a pyloric sphincter.