According to the currently available evidence, artificial sweeteners are not beneficial for health and weight management. Both animal and human studies indicate the consumption of artificial sugar substitutes increases the risk of diabetes and cardiovascular disease [1] with long-term consumption associated with weight gain and not weight loss [2], [3]. Although this may appear counterintuitive, it highlights the holistic approach to healthcare needed to manage these complex conditions. There are at least two ways artificial sweeteners contribute to this outcome

1. A negative interaction between the artificial sweeteners and the microbes which inhabit our gastrointestinal tract [4], [5]. Supporting the importance of healthy gut microbe profile in metabolic diseases such as obesity and diabetes [6] where  these microbes appear to communicate with our central nervous system to regulate appetite and eating behaviours [7].
2.  Another hypothesis is that these sweeteners induce a pavlovian response in which the taste of sweet foods is not matched with an appropriate calorie intake, disrupting the processes in the body which regulate food intake and energy balance [1]. 

Either way it appears that artificial sweeteners are not conducive to good metabolic health and their widespread consumption should be reassessed [4]. 

[1] S. E. Swithers, “Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements,” Trends Endocrinol. Metab., vol. 24, no. 9, pp. 431–441, Sep. 2013.

[2] S. P. Fowler, K. Williams, R. G. Resendez, K. J. Hunt, H. P. Hazuda, and M. P. Stern, “Fueling the obesity epidemic? Artificially sweetened beverage use and long-term weight gain.,” Obesity (Silver Spring)., vol. 16, no. 8, pp. 1894–900, Aug. 2008.

[3] M. N. Laska, D. M. Murray, L. A. Lytle, and L. J. Harnack, “Longitudinal associations between key dietary behaviors and weight gain over time: transitions through the adolescent years.,” Obesity (Silver Spring)., vol. 20, no. 1, pp. 118–25, Jan. 2012.

[4] J. Suez, T. Korem, D. Zeevi, G. Zilberman-Schapira, C. A. Thaiss, O. Maza, D. Israeli, N. Zmora, S. Gilad, A. Weinberger, Y. Kuperman, A. Harmelin, I. Kolodkin-Gal, H. Shapiro, Z. Halpern, E. Segal, and E. Elinav, “Artificial sweeteners induce glucose intolerance by altering the gut microbiota,” Nature, vol. 514, no. 7521, pp. 181–6, Sep. 2014.

[5] J. Suez, T. Korem, G. Zilberman-Schapira, E. Segal, and E. Elinav, “Non-caloric artificial sweeteners and the microbiome: findings and challenges.,” Gut Microbes, vol. 6, no. 2, pp. 149–55, Mar. 2015.

[6] T. H. Hansen, R. J. Gøbel, T. Hansen, and O. Pedersen, “The gut microbiome in cardio-metabolic health.,” Genome Med., vol. 7, no. 1, p. 33, Jan. 2015.

[7] V. Norris, F. Molina, and A. T. Gewirtz, “Hypothesis: bacteria control host appetites.,” J. Bacteriol., vol. 195, no. 3, pp. 411–6, Feb. 2013.