A new systematic review of 23 studies and over 1000 overweight people with diabetes found that low carb diets (70 to 120g carbs per day) resulted in more weight loss and better blood sugar control than the keto diet (less than 50g carbs per day).1 

The low carb diet only worked for the first 6 months and after that weight loss stopped. 

However, low carb diets that are high in animal foods have been linked to increased mortality. This was a meta-analysis published in The Lancet in 20182. It reported that low carbohydrate diets were associated with increased mortality, with minimal risk observed at 50% to 55% carbohydrate intake.  Low-carbohydrate diets that were rich in animal protein and fat were associated with higher mortality.

  1. Goldenberg JZ, Day A, Brinkworth GD, Sato J, Yamada S, Jönsson T, Beardsley et al. Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial dataBMJ. 2021 Jan 13;372:m4743. doi:10.1136/bmj.m4743
  2. Seidelmann SB, Claggett B, Cheng S, Henglin M, Shah A, Steffen LM, et al. Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysisLancet Public Health. 2018 Sep;3(9):e419-e428. doi:10.1016/S2468-2667(18)30135-X