Small amounts of fat under chin. What surgical options does a slim 140 pound guy have that could show natural features?

I suggest beginning with an in-person consultation to discuss your options. During your initial examination, your #chin will be evaluated along with the neck and jawline. A weak #chin implies a lack of chin support for the skin along the neck line. In younger individuals a chin implant alone is usually all that is needed to improve the appearance of the neck. Subsequently, it will also improve the overall #balance of the face and can create the illusion of a smaller nose. As a stand-alone procedure, chin augmentation can be performed in the office under local #anesthesia. For individuals with signs of #aging in the neck, a chin implant added to one of the recommended procedures above, will provide optimal results. Also, #liposuction under the chin is also another option your doctor can discuss. If you are not a candidate for chin or neck rejuvenation at the time of your #consultation, your board certified plastic surgeon can recommend alternatives to address your concern. 
However, there may be additional options to improve the appearance of your concern to improve the overall balance of your face. Such can be best evaluated in-person. Consulting with a board-certified plastic surgeon who specializes in #face, #neck and #chin procedures is important to ensure you are receiving the best advice, care, and surgical experience possible.

Chin Liposuction is the plastic surgery procedure that removes the excess of fat underneath the chin (double chin) and also along the inferior border of the jaw line. This allows to have a less "fat" neck specially when looking down (like when checkng the cell phone). In my practice I routinely perform chin liposuction under local anesthesia without sedation.

Hello and thank-you for sharing your question.
Correction of a double chin can be achieved either though a surgical or non-invasive approaches. Liposuction of the chin and neck produces consistently good results for appropriate candidates. We are very excited with the development of several non-invasive techniques for correction of a double chin. Ultherapy of the lower face and  submental neck can provide both skin tightening and fat reduction for more definition.  We also offer the Cool mini as a non-surgical alternative to liposuction for the right candidate. Generally, two treatments are required separated by 4-6 weeks.  We also offer Kybella which is another non-surgical alternative to liposuction. Generally 3-6 treatments are needed separated by 4-6 weeks.   
I would visit with a board certified plastic surgeon in your area to learn about your options..
Good Luck!