In the news: Meal Timing & Potential Weight Loss; Lutein, Lycopene & Skin Health

Meal Timing Gains Research Attention: Potential Weight Control Benefits?

According to the National Institutes of Health, more than two in three adults are considered to be overweight or obese. So it’s no surprise that developing weight loss strategies is a US research priority. One potential strategy was revealed last month by University of Alabama investigators at Obesity Week 2016, the largest international scientific conference on obesity and weight loss.

The timing of eating during the day has been shown to influence metabolism in animal models by reducing fat and lowering the animals’ risk of chronic diseases. The newly presented research (1) is the first to test this proposition in humans.

Called “early time restricted eating”, the idea is to eat a very early dinner or even skip dinner, keeping food intake within a shorter daily timeframe to better align with metabolic activities that function more optimally in the morning.

In the study, overweight or obese participants ate meals between 8 a.m. and 2 p.m. for four days, and then consumed the same number of calories for another four days, this time over the more traditional 8 a.m. through 8 p.m. time period. The amount of calories and fat burned and any impact on appetite was evaluated during the different eating schedules.

The ‘early time’ eating improved oxidation (burning) of fat for several hours at night and it also reduced daily ups and downs in hunger levels. It improved the ability to move between burning carbs and fat, which can be altered in people with insulin resistance – a condition that often accompanies being overweight.

Whether these preliminary findings will translate to a viable strategy for controlling weight is going to require larger studies for longer periods of time. The rationale for restricted early eating makes good scientific sense, but now we need to learn whether it can really help with weight loss and whether people can adapt to a change in meal times.
 
Healthy Skin from Within: Lutein & Lycopene

Everyone gets expression lines, thin wrinkles, and sagging skin as they grow older, which is partly determined by genetics. However, a chief reason for aging skin is "photo-aging" due to sun exposure.

Studies in animals and humans indicate that dietary carotenoids like lutein and beta carotene as well as the antioxidant vitamins C and E accumulate in the skin and play a role in the normal photo-protection of skin. A new study suggests that lycopene (abundant in tomatoes and tomato products) may also play a role.

In this crossover study (2), 65 volunteers were divided into 4 treatment groups. One group took 20 mg of lutein or placebo for 12 weeks then switched to the other treatment after a washout period. The second group was given 20 mg of lycopene or placebo for the same duration in the same fashion.

The placebo and active interventions were separated by a 2-week washout period. Skin was exposed to UV radiation. Both lycopene and lutein blocked the expression of genes that are indicators of oxidative stress and photo-aging.

Two important things to note: Consuming these carotenoids and antioxidants doesn’t mean that we don’t also need topical sunscreen protection as well – we do. Secondly, the high lutein level tested in this study does not appear necessary to offer normal skin protective activity. An earlier study (3) found that lower dose lutein (3 mg daily plus antioxidants) was just as effective as higher dose lycopene plus beta carotene (15 mg total, plus antioxidants) in hydrating skin and lowering oxidative stress in blood – a surrogate measure off UV effects on the skin.

References

1. Peterson C, et al. Time-restricted feeding increases fat oxidation and reduces swings in appetite levels in humans. Abstract T-OR-2081. Presented at: ObesityWeek 2016, Oct 31-Nov 4, 2016; New Orleans, LA.
2. Grether-Beck S, et al. Molecular evidence that oral supplementation with lycopene or lutein protects human skin against ultraviolet radiation: Resutls from a double-blinded, placebo-controlled, crossover study. Br J of Dermatol Epub ahead of print Sept 3, 2016.
   
3. Morganti P, et al. Protective effects of oral antioxidants on skin and eye function. SkinMed 3:310-16, 2004.