I don't recommend eating a 43% sucrose diet, but I do have interest in knowing how sugar affects human metabolism and behavior, as I think that this could help us understand the baseline adaptation of human metabolism.
Surwit et al did the experiment. The women weighed 130 to 200 percent of their ideal bodyweights at baseline. Surwit et al controlled dietary intake by providing the women with all meals and snacks consumed during the 6 week period, along with a Women's One-A-Day multivitamin.
Half of the women ate a starch-based diet and the other half ate the high sucrose diet. Each of the groups included 12 "whites." The high sucrose group had 8 "blacks," and the high starch group had 10.
This table shows the nutrient profile of the two diets; one supplied 121 g of sucrose daily, the other only 12 g sucrose daily:
You can see that without the multivitamin contribution, the high sucrose diet has a low nutrient density compared to the high starch diet. Of concern to me, with the multivitamin added, both groups had quite high intakes of iron. High levels of dietary and stored iron appear to promote multiple degenerative, inflammatory, and autoimmune disease processes, as well as aging, by enhancing oxidative activity throughout the body. Since these diets supplied essentially adequate dietary iron without the supplement, no one who did not have iron-deficiency anemia needed this amount of additional iron and I would have had them take an iron-free supplement in this study. Outside this study, I would have taught them to make natural food selections to optimize iron intake.
And this table shows a sample day's menu for each of the groups.
Lots of refined foods...not what I would suggest. Lots of room for improvement.
The following figure depicts the changes in body weight during the intervention:
Surprise! Both groups lost weight. According to this table, the loss included trunk fat and a decline in body fat percentage:
Total cholesterol, LDL, and triglycerides also declined, with minimal reduction in HDL:
Both groups had reductions in fasting glucose and marked reductions in levels of norepinephrine, a "fight or flight" neurotransmitter (declining levels of which would indicate reduction of perceived stress and tension):
"Interestingly, one 53-yold subject who displayed the typical pattern of markedly elevated plasma triacylglycerol and hyperglycemia at the beginning of the study showed significant decreases in fasting glucose, total cholesterol, LDL-cholesterol, and triacylglycerol concentrations, and an increase in HDL cholesterol during the 6 wk of the high-sucrose diet. These findings are consistent with epidemiologic data (1, 9, 22, 39) and animal data from our laboratory (13) that clearly show that high sucrose or complex carbohydrate consumption does not cause obesity, hyperglycemia, or insulin resistance in the absence of dietary fat."
Wait...with all that carbohydrate and so little fat and animal protein, didn't they feel hungry all the time? The following table shows the "behavioral"--actually, psychical, or mental-emotional-- effects of these diets:
The authors noted in the introduction:
"Although there is little theoretical rationale to support the notion that sucrose produces behavioral arousal, there are data to support a theory making the opposite prediction. Carbohydrate consumption, in conjunction with a minimal amount of protein, has been shown to cause an increase in the ratio of plasma tryptophan to large neutral amino acids (28), which in turn is associated with an increase in central tryptophan uptake and brain serotonin synthesis (29, 30). Furthermore, sucrose has a greater effect than starch. (28). This carbohydrate-induced change in central serotonin activity would presumably have a tranquilizing effect as opposed to the exaggerated arousal and hyperactivity typically attributed to sucrose (31). "Combined with this information, this study's findings that high sugar intakes can markedly reduce norepinephrine and hunger levels confirms the Chinese medical view that sugar has yin effects, where yin stands for the overlapping sensory characteristics cool, calm/quiet, soft, and moist. According to Chinese medicine, this makes sugar a medication for excessive yang conditions characterized by heat, agitation, tension, and dryness; but because it has relatively extreme characteristics, long term regular use of large amounts will create an excessively yin condition, i.e. excessive coolness, lassitude, weakness/impotence, and moisture (e.g. watery phlegm accumulation, excessive salivation), and a generally deficient condition. Chinese dietary principles classify whole food starches as more desirable, more balanced foods--having a balance of yin and yang characteristics making them suitable for use as staple foods. More on that in another article.
Meanwhile, this study seems to question claims that diets high in sugar or starch and low in fat will increase hunger, raise blood sugar, increase lipids, and promote metabolic syndrome in obese individuals. On the contrary, in this study, increasing the carbohydrate content of the diet, whether by starch or sugar, had the opposite effect.
It seems very unlikely that this would occur in any animal with a metabolism by nature designed for a low carbohydrate and high fat intake. I would expect high-carbohydrate, low-fat diet to increase, not decrease, stress and tension in an animal evolutionarily adapted to a low-carbohydrate, high-fat diet.
On the other hand, it suggests a dietary remedy to replace the most commonly prescribed drugs in the U.S.A. -- antianxiety and antidepressant medications.
Can you reverse depression, negative feelings, poor vigilance, and hunger all with one simple dietary shift to increased whole food starch and concomitant reduced fat?
A comprehensive theory of human nutrition and weight management has to have the capacity to explain this study without trying to explain it away.