Gluconeogenesis is a metabolic pathway that results in the generation of glucose fromnon-carbohydrate carbon substrates such as lactate, glycerol, andglucogenic amino acids.

So if you don't eat carbs, you body can still make the sugar you need to survive....

Thisstudy looked at why a high protein low carb diet increases yourresting metabolic rate....and explains much of the increase asaccounted for by gluconeogenesis.

Draw some conclusions.......

Gluconeogenesis and energy expenditure after a high-protein, carbohydrate-free diet

Background: High-protein diets have been shown to increase energy expenditure (EE).

Objective:The objective was to study whether a high-protein, carbohydrate-freediet (H diet) increases gluconeogenesis and whether this can explainthe increase in EE.

Design: Ten healthy men with a mean (±SEM)body mass index (in kg/m2) of 23.0 ± 0.8 and age of 23 ± 1 y receivedan isoenergetic H diet (H condition; 30%, 0%, and 70% of energy fromprotein, carbohydrate, and fat, respectively) or a normal-protein diet(N condition; 12%, 55%, and 33% of energy from protein, carbohydrate,and fat, respectively) for 1.5 d according to a randomized crossoverdesign, and EE was measured in a respiration chamber. Endogenousglucose production (EGP) and fractional gluconeogenesis were measuredvia infusion of [6,6-2H2]glucose and ingestion of 2H2O; absolutegluconeogenesis was calculated by multiplying fractionalgluconeogenesis by EGP. Body glycogen stores were lowered at the startof the intervention with an exhaustive glycogen-lowering exercise test.

Results:EGP was lower in the H condition than in the N condition (181 ± 9compared with 226 ± 9 g/d; P < 0.001), whereas fractionalgluconeogenesis was higher (0.95 ± 0.04 compared with 0.64 ± 0.03; P< 0.001) and absolute gluconeogenesis tended to be higher (171 ± 10compared with 145 ± 10 g/d; P = 0.06) in the H condition than in the Ncondition. EE (resting metabolic rate) was greater in the H conditionthan in the N condition (8.46 ± 0.23 compared with 8.12 ± 0.31 MJ/d; P< 0.05). The increase in EE was a function of the increase ingluconeogenesis (EE = 0.007 x gluconeogenesis – 0.038; r = 0.70, R2 =0.49, P < 0.05). The contribution of gluconeogenesis to EE was 42%;the energy cost of gluconeogenesis was 33% (95% CI: 16%, 50%).

Conclusions:Forty-two percent of the increase in energy expenditure after the Hdiet was explained by the increase in gluconeogenesis. The cost ofgluconeogenesis was 33% of the energy content of the produced glucose.